ENGINEERING 

OF 

SHOPS  AND  FACTORIES 


McGraw-Hill  BookGompaiiy 


Electrical  World         Ite  Engineering  andMinin^  Journal 
Engineering  Record  Engineering  News 

Railway  Age  Gazette  American  Machinist 

Signal  Engineer  American  Engneer 

Electric  Railway  Journal  Coal  Age 

Metallurgical  and  Chemical  Engineering  Power 


ENGINEERING 


OF 


SHOPS  AND  FACTORIES 


BY 

HENRY  GRATTAN  TYRRELL,  C.  E. 

Bridge  and  Structural  Engineer,  Evanston,  III.;  Member  of  the 

Western  Society  of  Engineers,  Society  for  the  Promotion 

of  Engineering  Education,  National  Geographic 

Society,  etc.;  Author  of:  Concrete  Bridges  and 

Culverts,  Mill  Buildings,   History  of 

Bridge   Engineering,  Artistic 

Bridge  Design. 


McGRAW-HILL   BOOK   COMPANY 

239  WEST  39TH  STREET,  NEW  YORK 

6  BOUVERIE  STREET,  LONDON,  E.  C. 

1912 


COPYRIGHTED,  1912 

BY 
-HENRY  GRATTAN  TYRRELL 


THE.  MAPLE.   PRES3.TOIIK.PA 


PREFACE 

This  book  is  based  upon  the  writer's  personal  observations, 
study  and  experience,  covering  a  period  of  more  than  twenty 
years  in  this  line  of  work.  It  is  a  sequel,  and  supplementary  to 
his  other  book  entitled  "Mill  Buildings/'  and,  excepting  in  a 
few  cases,  parts  which  are  fully  treated  there  are  not  repeated 
here.  Additional  information  and  costs  on  some  subjects  have 
been  included,  which  have  come  to  his  attention  since  his  last 
book  was  published. 

Chapter  I.,  entitled  "  Industrial  Engineers  and  Their  Services, " 
should  be  valuable  both  to  engineers  and  factory  owners, 
because  it  gives  the  standard  rules  of  conduct  and  business  which 
have  been  established  and  accepted  by  several  of  the  leading 
engineering  societies.  Similar  rules  have  long  existed,  governing 
the  relations  between  architects  and  contractors.  The  chapters 
on  the  economics  of  factory  location  and  construction  are 
included,  because  of  the  enormous  amount  of  money  being 
invested  in  manufacturing  industries.  If  these  plants  are,  at 
first,  wrongly  placed  or  arranged,  no  amount  of  subsequent  good 
management  can  remedy  the  initial  mistakes.  Several  chapters 
are  included  on  concrete  buildings  and  their  cost,  because  of  the 
increasing  use  of  this  material,  and  much- of  the  objection  to 
the  type  should  be  removed  by  the  explanation  of  easy  and 
effective  methods  of  surface  treatment  to  give  them  a  more 
attractive  appearance.  Such  details  as  foundations,  walls,  roof- 
ing, etc.,  which  are  fully  treated  in  the  author's  book  entitled 
"  Mill  Buildings,"  are  mentioned  only  briefly  here,  that  space  may 
be  left  for  other  subjects. 

Several  chapters  originally  contributed  by  the  writer  to  the 
Engineering  Magazine,  are  reproduced  with  little  or  no  change. 
In  order  to  make  the  book  of  greater  value,  some  of  the  chapters 
have  been  prepared  with  the  aid  of  specialists,  most  of  the  material 
on  Heating  and  Air  Washing  being  supplied  by  the  Buffalo  Forge 
Company,  and  that  on  Artificial  Lighting  by  the  Westinghouse 
Electric  Company.  Many  of  the  illustrations  are  from  the  pages 


292713 


vi  PREFACE 

of  Engineering  News,  Engineering  Record,  Railway  Age  Gazette 
and  other  journals. 

The  book  is  designed  to  aid  all  who  are  interested  in  shops 
and  factories,  and  especially  engineers,  architects,  draftsmen  and 
students,  as  well  as  factory  owners  and  employees. 

H.  G.  TYRRELL. 

EVANSTON,  ILLINOIS.  ». 

October,  1912. 


CONTENTS 

PAGE 

PREFACE     v 

INTRODUCTION xv 

CHAPTER  I 

ENGINEERS  AND  THEIR  SERVICES 1 

Building  Plans — By  Whom  Made — Cost  of  Engineering  Services — 
Rules  of  the  Engineers'  Club  of  St.  Louis — American  Institute  of 
Consulting  Engineers,  Code  of  Ethics — American  Institute  of 
Consulting  Engineers,  Schedule  of  Fees — Form  of  Contract  Between 
Engineer  and  Owner — Short  Form  of  Contract. 

CHAPTER  II 

MANUFACTURING  DISTRICT 12 

Selection  of  Manufacturing  District — City  or  Suburb — Cost  of 
Land — Labor  Supply — Nearness  to  Raw  Materials — Nearness  to 
Source  of  Power — Shipping  and  Freighting  Facilities — Climate — 
Market  for  Product — Selection  of  Building  Lot. 

CHAPTER  III 

ECONOMICS   OF  FACTORY  CONSTRUCTION 18 

Proposed  Methods  of  Manufacture — Methods  of  Management — 
Particulars  of  Similar  Plants — Schedule  of  Machinery — Arrange- 
ment of  Machines — Area  and  Elevation  of  Floors  in  Each  Depart- 
ment— Receiving,  Storing  and  Shipping  Facilities — Provision  for 
Expansion — Arrangement  for  Departments — Approximate  De- 
sign of  Buildings — Approximate  Cost  Estimates. 

CHAPTER  IV 

EXAMPLE  OF  PRELIMINARY  DESIGN 34 

Location — Size  of  Lot — Grading — Arrangement  of  Yard — Eco- 
nomic Production — Co-operation  with  Machine  Shop  and  Foundry 
— Scope  of  Plant — Future  Extension — Method  of  Constructing 
Buildings — Forge  Shop,  Building  and  Tools — Template  Shop, 
Building  and  Machinery — Riveting  Shop,  Building  and  Equip- 
ment— Loading  Facilities — Erecting  Tools  and  Machinery — 
power — Cost  of  Complete  Plant — Temporary  Plant,  Tools  Re- 
quired— Cost  of  Temporary  Plant — Profit  on  Investment. 


viii  TABLE  OF  CONTENTS 

CHAPTER  V 

PAGE 

GENERAL  DESIGN 42 

Aesthetic  Treatment  —  Wind  Pressures  —  Floor  Loads  —  Unit 
Stress — Stress  Analysis  in  Building  Frames — Knee  Braces — 
Specifications. 

CHAPTER  VI  ' 

SELECTION  OF  BUILDING  TYPE 52 

Kind  of  Building  Material — Essentials  of  Good  Framing — Vibra- 
tion and  Oscillation — Depreciation — Insurance — Roof  Outlines. 

CHAPTER  VII 

WOOD  AND  STEEL  FRAMING 61 

Timber  Framing — Cost  of  Timber  Framing — Steel  Framing — 
Framing  of  Domes — Long  Span  Roofs — Cost  of  Steel  Frame 
Buildings. 

CHAPTER  VIII 

CONCRETE  BUILDINGS ' 102 

Advantages  of  Concrete — Disadvantages  of  Concrete — Materials 
and  Mixing — Design — Permissible  Units — Separately  Moulded 
Members — Columns — Beams — Machinery  Connection  to  Floors — 
Shafting  Attachments — Waterproofing — Erection. 

CHAPTER  IX 

CONCRETE  SURFACE  FINISH      125 

Surface  Defects:  Hair  Cracks,  Porosity,  Dusting,  Irregularity  of 
Forms — Need  of  Treatment — Method  of  Treatment — Surface 
Coating:  Washing,  Painting — Veneering:  Brick  and  Stone  Facing, 
Plastering,  Stucco — Surface  Removal,  Coloring,  Preparation  of 
Surface:  Sand  Blasting,  Tooling,  Rubbing,  Picking,  Scrubbing, 
Pebble  Dashing,  Acid  Etching. 

CHAPTER  X 

COST  OF  REINFORCED  CONCRETE  BUILDINGS 140 

Cost  of  Buildings — Cost  Analysis  of  Concrete  and  Forms. 

CHAPTER  XI 

COMPARATIVE   COST   OF   WOOD,    REINFORCED   CONCRETE   AND   STEEL 

BUILDINGS 147 

First  Cost — Ultimate  Cost — Wood  and  Reinforced  Concrete 
Compared — Reinforced  Concrete  and  Steel  Compared. 

CHAPTER  XII 

FOUNDATIONS 152 

Loads  on  Foundations — Bearing  Power  of  Soils — Area  on  Soil — 
Foundation  Walls — Piers — Piles — Machinery  Foundations. 


TABLE  OF  CONTENTS  ix 

CHAPTER  XIII 

PAGE 

GROUND  FLOORS 158 

Earth  Floors — Wood  Blocks — Plank  Floors — Tar-concrete  and 
Wood — Cement-concrete  Floors — Granolithic  Finish — Asphalt — 
Brick — Recommended  Types. 

CHAPTER  XIV 

UPPER  FLOORS 172 

Slow-burning  Wood  Floors — Safe  Load  on  Plank — Wood  Floors 
with  Steel  Beams — Triangular  Sheet  Steel  Floors — Multiplex 
Floors — Metal  Arches — Metal  Troughs — Plate  Floors — Brick 
Arches. 

CHAPTER  XV 

CONCRETE  UPPER  FLOORS 178 

Concrete  Beams  and  Wood  Flooring — Floors  with  Concrete 
Beams  and  Slabs— Flat  Slab  Floors— Thickness  of  Flat  Slabs. 

CHAPTER  XVI 

WALLS,  PARTITIONS  AND  OPENINGS 188 

Brick  Walls— Vitrified  Tile  Walls— Concrete  Block  Walls— Cem- 
ent Brick  Walls — Monolithic  Concrete — Wooden  Framing — 
Comparative  Cost  of  Frame,  Veneer  and  Brick  Walls — Partitions — 
Windows — Doors. 

CHAPTER  XVII 

ROOFS  AND  ROOFING 199 

Roof  Covering — Thickness  of  Roof  Boards — Concrete  Roofs — -Con- 
crete Shingles — Concrete  Tiles. 

CHAPTER  XVIII 

SPECIAL  BUILDINGS — NOTES  ON 203 

The  Drafting  Office — Machine  Shops — Forge  Shops — Foundries — 
Engine  or  Roundhouses — Car  Sheds — Car  Houses — Cotton  Mills — 
Power  Houses. 

CHAPTER  XIX 

STORAGE  POCKETS  AND  HOISTING  TOWERS  .    .    : 219 

Hoisting  Towers. 

CHAPTER  XX 

FACTORY  HEATING 229 

Apparatus  for  Fan  System — Heat  Losses — Fan  System  and 
Direct  Radiation  Compared— Systems  of  Air  Supply — Systems  of 
Air  Distribution — Advantages  of  the  Fan  System — Utilization  of 
Waste  Heat — Air  Economizer — Heating  with  Exhaust  Steam — 


x  TABLE  OF  CONTENTS 

PAGE 
CHAPTER  XX  (CONTINUED) 

Flexibility  of  Operation — First  Cost — The  Vacuum  System — 
Roundhouse  Installation — Application  to  Textile  Mills — Fan  Sys- 
tem in  Paper  Mills — Fan  System  in  Paint  Shops — Steam  Heating — 
Heating  by  Floor  Radiation. 

CHAPTER  XXI     - 

AIR  WASHING  SYSTEMS 251 

Construction  of  Eliminators — Action  of  Eliminators — Spray  Cham- 
bers— Pumps — Hygrodeik — Gas  Heaters — General  Arrangement — 
Operation. 

CHAPTER  XXII 

FACTORY  LIGHTING 257 

The  Candle-power  of  Units — Relation  of  Lighting  Problems  to 
Efficient  Management — Importance  of  Good  Illumination  in  Fac- 
tory Work — Relative  Cost  Factors  of  Light — General  Require- 
ments— Items  Bearing  on  Effective  Illumination — Classification  of 
Problems  in  Factory  Work — Overhead  Method  of  Lighting — 
Examples — Glare — Shielding  Effect  of  Girders — Selection  of 
Lamps — Number  of  Lamps  per  Unit  of  Floor  Space — 250- Watt 
versus  100- Watt  Units — Size  of  Lamps — Mounting  Height  of 
Units  Above  Floor — Illumination  of  Vertical  Surfaces — Reflectors 
for  Uniform  Illumination:  Test  for  Uniformity,  Value  of  Light 
Ceilings,  Lighting  Circuits,  Switch  Control — Placing  of  Switches — 
The  Working  Drawing — Maintenance  Problems:  Cleaning  Reflec- 
tors, Cost  Comparisons,  Illumination  Data — Typical  Factory 
Lighting  Problem:  Lighting  Requirements,  Experiments  and 
Steps  Leading  to  Final  Arrangement,  Notes  on  Final  Arrangement — 
Comments  on  Lighting  System. 

CHAPTER  XXIII 

DRAINAGE   OP  INDUSTRIAL  WORKS 281 

The  Drainage  of  Buildings — The  Drainage  of  Plants — Ventilation 
of  Sewers — Flushing  of  Sewers — Pneumatic  System — Conserva- 
tion of  Sewage — Final  Disposal  of  Sewage. 

CHAPTER  XXIV 

WATER  SUPPLY  AND  STORAGE  TANKS 297 

Comparative  Designs — Selection  of  Style — Standard  Dimensions 
for  Steel  Tanks — Capacity  of  Cylindrical  Tanks — Capacity  of 
Pumps — Horsepower  Required  to  Raise  Water  to  Different 
Heights — Fire  Streams — Friction  of  Water  in  Pipes. 

CHAPTER  XXV 
STEEL   CHIMNEYS   .  316 


LIST  OF  TABLES  xi 

CHAPTER  XXVI 

PAGE 

FIRE   PROTECTION 319 

Methods  of  Protection — Fireproof  Materials — Arrangement  of 
Departments — Protective  Systems — Inspection — Fire  Drill. 

CHAPTER  XXVII 

CRANES      327 

Hand  Traveling  Shop  Crane — Specification  for  Hand  Traveling 
Cranes. 

CHAPTER  XXVIII 

YARDS   AND  TRANSPORTATION 330 

Track  Arrangement — Motors — Loading  and  Conveying  Apparatus. 

CHAPTER  XXIX 

ESTIMATES 336 

Single-story  Metal  Working  Shops — Multi-story  Automobile  Fac- 
tory. 

CHAPTER  XXX 

CONSTRUCTION 354 

Estimates  and  Tenders — Contracts — Superintendence. 

CHAPTER  XXXI 

WELFARE  FEATURES 357 

Social  Relations — Health  Conditions — Pleasant  Surroundings — 
Material  Benefits — Educational  Advantages — Opportunity  for 
Recreation. 

CHAPTER  XXXII 

STANDARD   BUILDINGS 364 

BIBLIOGRAPHY 389 

INDEX  ...   395 


LIST  OF  TABLES 

TABLE  PAGE 

I.  Approximate  Insurance  Charges 54 

II.  Approximate  Insurance  Charges 55 

III.  Strength  of  Spikes  and  Nails 64 

IV.  Cost  of  Wood  Buildings 67 

V.  Weight  of  Steel  in  Multi-story  Buildings 100 

VI.  Cement  Production  in  the  United  States 103 

VII.  Comparative  Cost  of  Monolith  and  Unit  Concrete  Systems  .  115 

VIII.  Cost  of  Color  Pigments 132 

IX.  Cost  of  Reinforced  Concrete  Buildings 141 

X.  Cost  of  Reinforced  Concrete  Buildings 142 

XI.  Cost  Analysis  of  Concrete  Buildings 143 

XII.  Comparative  Cost  of  Wood  and  Reinforced  Concrete      .    .  149 

XIII.  Comparative  Cost  of  Reinforced  Concrete  and  Steel   .    .    .  151 

XIV.  Bearing  Power  of  Soils 153 

XV.  Safe  Load  on  Plank       172 

XVI.  Safe  Load  on  Multiplex  Steel  Plate  Floors 175 

XVII.  Thickness  of  Flat  Slal?s 185 

XVIII.  Cost  of  Veneer,  Frame  and  Solid  Walls .    .  193 

XIX.  Roof  Coverings .    .  199 

XX.  Strength  of  Roof  Boards      .    .    .    : 200 

XXI.  Weight  of  Galvanized  Iron  Pipes 245 

XXII.  Carrying  Capacity  of  Pipes 247 

XXIII.  Lighting  Systems 274 

XXIV.  Dimensions  of  Tanks 310 

XXV.  Capacity  of  Tanks 311 

XXVI.  Capacity  of  Pumps 312 

XXVII.  Required  Horsepower  to  Raise  Water 313 

XXVIII.  Fire  Streams 314 

XXIX.  Friction  of  Water  in  Pipes 315 

XXX.  Standard  Buildings— Size  of  Material 367 

XXXI.  Standard  Buildings— Roof  Trusses •  .    .  374 

XXXII.  Standard  Buildings — Monitor  Framing 375 

XXXIII.  Standard  Buildings— Side  Posts  and  Knee  Braces  ....  376 

XXXIV.  Standard  Buildings — End  Panel,  Roof  Purlins     .    .-    .  '  .    .  378 
XXXV.  Standard  Buildings— Intermediate  Panel,  Roof  Purlins .  v  379 

XXXVI.  Standard  Buildings — Ends  of  Buildings — Diagrams  .    .  *.  380 

XXXVII.  Standard  Buildings— Ends  of  Buildings— Sizes 381 

XXXVIII.  Standard  Buildings— Rafter  Bracing 383 

XXXIX.  Standard  Buildings— Tie  Beam  Bracing 384 

XL.  Standard  Buildings — Connection  Details 385 

XLI.  Standard  Buildings— Material  for  Side  Posts 386 

XLII.  Standard  Buildings— Side  Purlins 388 

xiii 


INTRODUCTION 

The  building  of  shops  and  factories  has  developed  in  the  last 
few  years  into  one  of  the  largest  branches  of  modern  business. 
Those  who  were  formerly  content  to  carry  on  manufacturing  in 
shops  of  the  old  type  have  long  since  discovered  that  the  build- 
ings themselves  can  be  made  one  of  the  largest  factors  in  economic 
production,  and  more  adequate  ones  are  everywhere  in  evidence. 
Goods  of  great  value  were  formerly  made  and  stored  in  buildings 
which  were  improperly  lighted,  heated  and  ventilated,  and  liable 
at  any  time  to  be  destroyed  by  fire.  As  a  partial  protection 
against  loss,  heavy  insurance  was  often  carried,  with  a  corre- 
sponding charge  against  the  business.  From  inadequate 
ventilation,  the  building  interiors  were  often  smoky  and  dusty, 
and  valuable  goods  were  in  constant  danger  of  being  soiled.  In 
many  cities  and  districts,  especially  where  soft  coal  was  used  for 
fuel,  the  atmosphere  was  loaded  with  smoke,  and  the  depreciation 
of  goods  was  often  a  serious  loss. 

The  planning  and  arranging  of  plants  was  formerly  done  by 
their  owners  or  managers,  who  made  little  or  no  provision  for 
their  extension  or  development,  and  who  considered  that  business 
success  depended  wholly  upon  good  management.  It  was  then 
the  belief  that  the  buildings  were  of  little  importance,  but  it  is  now 
well  known  that  they  can  and  should  be  arranged  and  designed 
to  facilitate  production  to  the  greatest  extent.  As  the  building 
of  plants  has  increased,  and  steel  and  concrete  have,  to  a  large 
extent,  replaced  wood  as  a  structural  material,  the  assistance  of 
engineers  and  architects  have  been  sought,  not  only  in  planning 
the  buildings,  but  in  installing  and  arranging  their  equipment. 
Business  in  this  direction  has  increased  to  such  an  extent  as  to 
give  employment  to  a  large  number  of  men  known  as  Industrial 
Engineers,  who  are  especially  trained  in  the  planning  and  building 
of  shops  and  factories.  These  men,  giving  special  study  to  the 
economics  of  manufacturing  plants  both  as  to  construction  and 
operation,  are  frequently  able  in  addition  to  other  services,  to 
give  valuable  advice  and  assistance  to  owners. 

XV 


xvi  INTRODUCTION 

Enterprises  have  usually  begun  in  rented  space  or  in  small 
buildings  owned  by  their  occupants,  and  extensions  are  generally 
the  outcome  of  small  beginnings.  New  shops  may  consist  of 
additions  to  old  plants,  or- .entirely  new  buildings  may  be  erected 
on  a  more  commodious  site,  the  latter  method  giving  the  largest 
opportunity  for  economic  design  and  arrangement.  The 
efficiency  of  a  new  plant,  or  its  capability  of  producing  at  mini- 
mum cost,  depends  to  a  great  extent  on  the  thought  and  study 
which  has  been  given  to  shop  economics,  previous  to  the  begin- 
ning of  building  operations.  Efficiency  is  greatly  '"hindered 
when  a  building  is  unsuited  to  its  use,  and  defects  which  are 
discovered  after  completion  are  usually  too  Expensive  to  remedy. 
The  need  is,  therefore,  evident  for  very  careful  planning  and 
study  before  beginning  the  detail  drawings,  and  such  investiga- 
tions are  by  far  the  most  important  part  of  the  engineer's  work. 
The  building  should  be  considered  merely  as  a  part  of  one  great 
industrial  machine,  the  various  men  and  tools  all  fulfilling  their 
respective  duties,  and  working  harmoniously  together  with  the 
greatest  efficiency  and  the  least  total  cost. 

To  have  any  prospects  of  successful  operation,  amid  present 
industrial  competition,  a  plant  must  be  in  an  advantageous 
district,  must  be  economically  designed  and  well  arranged,  and 
have  low  maintenance  cost.  When  these  ends  are  attained,  its 
further  success  will  depend  upon  good  judgment  and  careful 
buying,  combined  with  other  established  principles  of  business, 
such  as  reputation  for  honesty  and  fair  dealing. 

The  extent  and  importance  of  manufacturing  industries  can 
best  be  appreciated  by  a  consideration  of  the  following  approxi- 
mate data  relating  to  the  whole  United  States. 

Number  of  manufacturies 240,000 

Capital  invested $21,000,000,000 

Number  of  employees 7,000,000 

Wages  earned  per  year $  4,000,000,000 

Value  of  materials  used $18,000,000,000 

Value  of  produsts $30,000,000,000 

The  approximate  costs  given  throughout  the  book  apply  only 
to  the  conditions  given,  and  will  change  according  to  the  time 
and  place  and  with  the  local  rate  of  wages  and  the  cost  of  building 
supplies.  Prices  in  the  Northern  States  are  quite  different  to 
those  in  the  Southern  and  Western  States,  and  may  hardly 


INTRODUCTION  xvii 

approximate  those  obtainable  in  other  countries.  They  must, 
therefore,  be  used  with  great  caution,  for  otherwise  they  may 
lead  to  serious  errors.  When  estimating  costs,  the  engineer 
should  familiarize  himself  with  prices  and  conditions  in  the  dis- 
trict where  goods  and  labor  must  be  purchased. 


ENGINEERING  OF  SHOPS  AND  FACTORIES 

CHAPTER  I 
ENGINEERS  AND  THEIR  SERVICES 

Building  Plans.  By  Whom  Made. — When  a  company  has 
decided  to  erect  new  buildings  or  extensions,  the  work  is  usually 
wanted  in  the  shortest  time  possible.  One  of  the  first  duties  of 
the  company  will  be  the  selection  of  one  or  more  men  to  work 
out  the  plans.  This  work  is  sometimes  divided  between  two 
men  or  sets  of  men,  the  first  being  mechanical  or  plant  engineers 
and  the  others,  structural  engineers,  each  group  of  men  being 
trained  in  a  special  line  of  work.  In  other  cases  the  whole  work 
is  undertaken  by  one  engineer  or  engineering  firm.  When  a 
plant  engineer  is  first  employed,  it  is  his  duty  to  investigate  all 
matters  pertaining  to  the  arrangement  of  machinery  and  depart- 
ments, and  to  carry  on  preliminary  studies  as  outlined  in  Chapters 
II  and  III,  under  the  direction  of,  and  in  consultation  with  the 
plant  owners.  He  will,  in  fact,  outline  the  whole  scheme  and 
furnish  the  structural  engineer  with  preliminary  plans  and 
approximate  cost  estimates.  (See  Tyrrell's  Mill  Buildings, 
page  12.)  This  greatly  simplifies  work  for  the  structural 
engineer,  as  his  duties  then  relate  chiefly  to  matters  of  building 
construction  and  economic  design. 

When  the  whole  work  of  planning  a  plant,  including  the 
preliminary,  mechanical  and  constructive  details  is  entrusted  to 
one  man  or  firm,  the  duties  of  the  engineer  are  greatly  enlarged 
and  it  is  this  condition  which  is  assumed  in  the  following 
discussion. 

When  looking  about  for  persons  to  make  investigations  and 
prepare  designs  and  drawings,  the  plant  owner  usually  finds 
that  this  work  may  be  done  in  at  least  four  different  ways. 

1.  By  the  company's  draftsmen  under  the  direction  of  the 
owner. 

2.  By  the  company's  draftsmen  under  the  supervision  of  a 
specially  employed  industrial  engineer. 

3.  By  a  contracting  firm  expecting  to  secure  a  contract  for 
construction. 

4.  By  a  consulting  engineer  or  firm,  with  staff  assistance. 

1 


2         ENGINEERING  OF  SHOPS  AND  FACTORIES 

1.  The  first  of  these  methods  often  appears  to  owners  to  be 
the  cheapest  and  most  attractive,  for  plans  would  then  be  ob- 
tained at  cost  price.     The  disadvantage  is,  that  shop  draftsmen 
accustomed   to   working   on   machinery   parts,   are,   as   a   rule, 
unfamiliar  with  building  construction,  and  the  owner  or  manager 
who  may  be  thoroughly  familiar  with  manufacturing  methods 
and  works  management,  even  though  4ie  may  in  earlier  years 
have  been  an  expert  draftsman,  no  longer  has  time  to  keep 
himself  informed  on  such  matters.     Another  disadvantage  of 
this  method  is  that  the  owner  and  his  drafting  force».are  not  in 
possession  of  data  pertaining  to  manufacturing  plants  in  general, 
and  their  time  is  too  fully  occupied  with  other  duties  to  permit 
them  to   concentrate  thought  on  this  important  work.     The 
successful  manager  of  a  woolen  mill  would  certainly  not  attempt 
to  manufacture  the  machinery  for  his  mill,  and  for  the  same 
reason  he  can  hardly  be  expected  to  proficiently  design  the 
details  of  factory  building. 

2.  The  second  method  of  securing  plans,  in  which  the  owner 
employs  an  industrial  engineer  to  work  out  the  designs  and 
drawings  with  the  assistance  of  the  plant  draftsmen,  is  unsatis- 
factory for  the  same  reason  as  stated  before,  that  such  men  are 
rarely  familiar  with  structural  work  or  building  construction. 
If  special  draftsmen  are  employed  under  the  direction  of  an 
industrial  engineer,  the  result  is  practically  the  same  as  when  a 
consulting  engineer  or  firm  is  employed,  for,  if  proficient,  he 
will  expect  responsible  charge.     If  he  is  not  thoroughly  proficient 
and  is  willing  to  give  his  services  for  little  more  than  draftsmen 
receive,  it  is  hardly  probable  that  a  works  manager  would,  on 
second  thought,  be  willing  to  entrust  him  with  the  planning  of 
buildings  involving  the  expenditure  of  a  large  sum  of  money. 
The  law  of  economic  construction  should  be  remembered,  which 
is — that  in  the  building  of  plants,  the  greatest  efficiency  and 
economy  are  obtained  only  when  the  work  is  under  the  direction 
of  a  thoroughly  proficient  and  experienced  person. 

3.  The  acceptance  by  an  owner  of  a  competitive  design  (Fig.  1) 
from  a  firm  hoping  to  receive  a  contract  for  the  work,  is  ques- 
tionable  practice   and   often  unsatisfactory.     Contractors  who 
make  a  practice  of  getting  work  in  this  way,  expecting  to  secure 
only  part — perhaps  one-fifth — of  all  work  for  which  they  make 
plans,  must  add  to  each  bid,  the  cost  of  making  plans  for  the 
other  four-fifths.     Therefore,  instead  of  paying  for  one  set  of 


ENGINEERS  AND  THEIR  SERVICES  3 

plans,  the  owner  must  really  pay  for  at  least  five  sets,  with  a 
possible  increase  to  ten  or  more,  if  the  contractor  is  successful  in 
a  less  number  of  cases.  To  compensate  for  this  contracting 
expense,  and  yet  keep  the  cost  down  to  what  it  would  be  if  there 
was  only  one  set  of  plans  to  pay  for,  the  contractor  must  use 
cheaper  or  lighter  material,  with  a  corresponding  reduction  in 
strength.  On  the  other  hand,  if  the  owner  receives  plans  from 
only  one  contractor  and  awards  a  contract  on  a  unit  or  tonnage 
basis,  he  may  then  be  obliged  to  pay  for  extra  weight  or  material. 
A  structural  company  for  which  the  writer  was  engineer,  once 
received  a  contract  for  several  large  steel  frame  buildings  on  a 


FIG.  1. — Factory  building  for  Scott  &  Bowne,  Bloomfield,  N.  J. 

tonnage  basis,  and  instead  of  supplying  the  purchaser  with  a 
rational  design,  the  proprietors  of  the  structural  company 
insisted  on  using  excess  material  to  such  an  extent  that  riveted 
steel  columns  were  made  of  plates  and  angles  f  in.  thick, 
when  yV-in.  thickness  was  sufficient,  with  corresponding  waste 
in  other  parts. 

A  better  way  of  securing  plans  is  to  employ  a  competent  and 
conscientious  structural  engineer  whose  only  object  will  be  to 
serve  the  best  interests  of  his  client.  The  owner  should  then  get 
the  best  results  that  are  obtainable  and  pay  only  for  service  which 
he  receives.  Better  results  usually  follow  by  leaving  details  of 


4         ENGINEERING  OF  SHOPS  AND  FACTORIES 

construction  to  the  engineer,  who  is  better  qualified  than  the 
owner  to  make  such  selection.  The  employment  of  a  consulting 
engineer  may  result  in  a  larger  amount  of  money  being  paid  for 
engineering  service,  than  if  such  work  were  attempted  or  done 
by  draftsmen  in  the  owner's  office;  but  if  the  consulting  engineer 
is  honest  and  proficient,  he  should  give  value  many  times  for 
the  money  received,  and  the  "result  should  be  better  service  and 
lower  ultimate  cost.  The  rule  previously  stated  will  nearly 
always  apply — that  the  greatest  degree  of  efficiency  and  economy 
on  construction  work  is  secured  only  when  it  is  under  the  direc- 
tion of  an  experienced,  proficient  and  conscientious  person. 
Such  men,  by  their  superior  knowledge  are  able  to  save  money  for 
their  clients,  and  to  show  results  corresponding  to  the  degree  of 
confidence  which  can  be  placed  upon  them. 

The  qualities  needed  in  an  industrial  engineer  are  knowledge 
and  experience,  together  with  enough  force  of  character  to  claim 
and  hold  the  confidence  of  those  with  whom  he  is  doing  business. 
He  must  be  able  to  design,  illustrate  and  superintend  his  work, 
or  to  direct  others  in  such  duties.  While  he  must  have  a  general 
knowledge  of  his  whole  business,  he  should  have  among  his 
assistants,  men  specially  trained  in  different  kinds  of  work,  as, 
for  instance,  one  or  more  draftsmen  on  mechanical  equipment, 
another  on  architectural  drawings  and  perspectives. 

The  word  " engineer"  is  used  instead  of  " architect/'  in  the 
above  discussion,  for  industrial  problems  pertaining  chiefly  to 
construction  and  efficiency  are  better  understood  by  engineers 
than  architects.  It  is  true  that  many  persons  calling  themselves 
"architects"  are  among  the  most  skillful  workers  on  industrial 
plants,  but  these  persons  might  better  be  called  engineers  rather 
than  architects,  since  architecture  is  usually  accepted  as  relating 
more  particularly  to  the  esthetics  of  design  and  construction. 
The  results  have,  however,  been  excellent,  for  factory  buildings 
are  now  made  which  are  not  only  serviceable  but  also  ornamental. 

The  works  management  should  delegate  some  one  person  to 
represent  them  in  all  matters  pertaining  to  the  new  buildings, 
so  there  may  be  no  misunderstanding  of  orders.  This  person 
should  clearly  explain  to  the  engineer  all  requirements  of  the 
owners,  and  should  thoroughly  inform  him  on  all  matters  that 
are  not  clear  to  him. 

Cost  of  Engineering  Service. — In  the  following  paragraphs,  it 
is  assumed  as  axiomatic  that  the  best  service  with  greatest 


ENGINEERS  AND  THEIR  SERVICES  5 

efficiency  and  least  cost  is  obtained  from  those  who  are  compe- 
tent, experienced  and  conscientious,  even  though  these  qualities 
are  often  hard  to  find  in  one  person.  Owners  are  usually  unwill- 
ing to  entrust  important  matters  involving  the  expenditure 
of  large  sums  of  money,  to  novices  or  beginners.  It  may,  there- 
fore, be  assumed  that  in  employing  an  engineer,  the  owner  will 
prefer  a  man  whose  experience  and  ability  would  enable  him  to 
earn  an  income  of  at  least  $4500  to  $6000  per  year,  or  $15  to  $20 
per  day.  He  should  in  any  case  be  paid  enough  to  place  him 
beyond  the  need  of  resorting  to  questionable  transactions  in 
order  to  make  a  living.  As  the  general  expense  of  an  engineering 
office  will  amount  to  about  as  much  as  the  bill  of  wages,  the 
actual  cost  without  profit  for  the  services  of  such  an  engineer 
alone  would  be  $30  to  $40  per  day.  Minimum  charges  of  $40  to 
$50  per  day  are  therefore  quite  reasonable. 

The  following  are  the  charges  made  a  few  years  ago  by  a  firm 
of  architects  and  engineers  where  the  writer  was  chief  engineer, 
the  percentage  being  on  the  total  cost  of  work. 

SCHEDULE  OF  CHARGES 

Preliminary  studies  only 1      per  cent. 

Preliminary  studies,  general  drawings  and  specifications 2|    per  cent. 

Preliminary  studies,  general  drawings,  specifications  and 

details 3J    per  cent. 

Full  professional  services  including  supervision 5      per  cent. 

Commission  computed  on  entire  cost  of  work. 

Traveling  expenses  to  be  paid  by  clients. 

Two  and  one-half  per  cent,  is  due  when  drawings  and  specifica- 
tions are  ready  for  contractors,  and  1^  per  cent,  when  con- 
tract is  let. 

Under  present  prices  (1912)  a  commission  of  5  per  cent,  should 
apply  only  to  very  large  and  plain  buildings  without  much  de- 
tail. For  smaller  buildings  or  more  complicated  ones,  the 
commission  should  be  not  less  than  6  per  cent.  In  preliminar}^ 
work,  as  it  is  often  difficult  to  determine  the  value  upon  which 
to  base  the  engineer's  commission,  it  may  be  more  definite  and 
satisfactory  to  undertake  such  work  on  a  fixed  charge  per  day  for 
the  engineer,  with  extra  compensation  for  each  assistant,  travel- 
ing or  other  extra  expenses  to  be  paid  by  the  owners. 

The  customary  charges,  and  agreements  between  owners  and 
engineers,  can  best  be  shown  by  giving  the  regulations  of  several 
Engineering  Societies. 


6        ENGINEERING  OF  SHOPS  AND  FACTORIES 

PROFESSIONAL   SERVICES   OF   CONSULTING   AND   CONSTRUCTION 

ENGINEERS 

(Engineers  Club  of  St.  Louis.) 

Schedule  of  Charges. — The  following  schedule  of  charges  is 
intended  as  a  guide  to  engineers  ,and  their  clients.  It  is  adopted 
as  representing  fair  and  proper  compensation  for  engineering 
services  under  the  conditions  stated,  and  is  believed  to  conform 
to  the  established  practice  of  leading  American  engineers.  The 
propriety  of  a  per  diem  or  percentage  charge  is  recognized, 
varying  in  amount  according  to  the  magnitude  or  importance  of 
the  work  involved,  or  the  experience  and  reputation  of  the 
engineer.  The  right  is  reserved  to  depart  from  the  schedule  at 
any  time  if  such  action  seems  wise  and  proper. 

1 .  For  preliminary  study  and  report  upon  a  proj  ect,  or  examina- 
tion of  a  project  prepared  by  another  engineer  and  a  report  on  same : 

a.  Charges,  $50  to  $100  per  day  for  the  first  two  to  ten  days, 
and  $25  to  $50  per  day  thereafter,  plus  all  expenses,  including 
salaries  paid  assistants  with  an  allowance  of  25  per  cent,  of  such 
salaries  for  general  office  expenses. 

b.  In  lieu  of  the  above,  at  the  option  of  the  engineer,  a  percent- 
age charge  varying  from  1  to  2£  per  cent. 

2.  For  preliminary  study,  report  and  final  detail  drawings  and 
specifications: 

Charges  same  as  under  paragraph  (1  a)  or  at  the  option  of  the 
engineer,  charges  of  3J  per  cent. 

3.  For  preliminary  study  and  report,  preparing  detail  drawings 
and  specifications,  awarding  contracts  and  acting  in  a  general 
supervisory  capacity  during  construction,  including  office  con- 
sultation but  not  including  continuous  supervision,  inspection, 
testing  or  management-work  costing  $10,000  or  more,  5  per  cent. 

For  work  costing  less  than  $10,000,  it  is  proper  to  charge  a  fee 
in  excess  of  5  per  cent. 

4.  For  full  professional  services  and  management,  including 
preliminary  studies,  detailed  drawings  and  specifications,  award- 
ing contracts,  active  and  continuous  supervisions,  testing  and 
inspection — work  costing  $10,000  or  more,  10  per  cent. 

For  work  costing  less  than  $10,000,  it  is  proper  to  charge  a 
fee  in  excess  of  10  per  cent. 

5.  For  investigations  and  reports  involving  questions  in  dispute 
and  intended  for  use  in  connection  with  expert  testimony: 


ENGINEERS  AND  THEIR  SERVICES  7 

Charges. — A  minimum  fee  or  retainer  of  $100  to  $500  or  such 
larger  amounts  as  may  be  commensurate  with  the  financial 
importance  of  the  case  or  the  labor  involved,  with  per  diem  and 
expense  charges  as  per  paragraph  (1  a). 

6.  Where  a  per  diem  charge  is  made,  six  hours  of  actual  work 
shall  be  considered  one  day.     While  absent  from  the  home  city, 
however,  or  while  attending  court,  each  day  of  twenty-four  hours 
or  part  of  a  day  shall  be  considered  one  day,  irrespective  of  the 
actual  hours  of  time  devoted  to  the  case. 

7.  When  charges  are  based  on  a  percentage  of  the  cost,  the 
commissions  as  above  are  to  be  computed  on  the  entire  cost  of  the 
completed  work  or  on  the  estimated  cost  pending  execution  or 
completion.     Payments  shall  be  made  to  the  engineer  from  time 
to  time  in  proportion  to  the  amount  of  work  he  has  done. 

8.  Traveling  expenses  as  well  as  any  expenses  involved  in  the 
collection  of  the  data  necessary  for  the  proper  designing  or  plan- 
ning of  the  structure  or  project  such  as  borings,  soundings  or 
other  tests,   and   excepting   only  ordinary  measurements   and 
surveys,  are  to  be  paid  by  the  client  in  addition  to  the  commissions 
herein  provided. 

9.  When    alterations    or    additions    are    made   to    contracts, 
drawings   or  specifications,   or  when  services   are   required    in 
connection  with  legal  proceedings,  failure  of  contractors,  fran- 
chises or  right  of  way,  a  charge  based  upon  the  time  and  trouble 
involved  shall  be  made  for  same  in  addition  to  the  commission 
herein  provided  for. 

10.  Drawings   and    specifications    are   to   be   considered   the 
property  of  the  engineer,  but  the  client  is  entitled  to  receive  one 
complete  record  copy  of  same  upon  payment  of  actual  cost  of 
making  copies,  if  no  duplicate  set  is  on  hand. 

PROFESSIONAL  CODE  AND  SCHEDULE  OF  FEES  FOR  CONSULTING 
ENGINEERS,  ADOPTED  JUNE  29,  1911 

(The  American  Institute  of  Consulting  Engineers,  New  York) 

Code  of  Professional  Ethics. — It  shall  be  considered  unprofes- 
sional and  inconsistent  with  honorable  and  dignified  bearing  for 
any  member  of  the  American  Institute  of  Consulting  Engineers: 

1.  To  act  for  his  clients  in  professional  matters  otherwise  than 
in  a  strictly  fiduciary  manner  or  to  accept  any  other  remuneration 
than  his  direct  charges  for  services  rendered  his  clients  except 
as  provided  in  Clause  4. 


8         ENGINEERING  OF  SHOPS  AND  FACTORIES 

2.  To  accept  any  trade  commissions,  discounts,  allowances, 
or  any  indirect  profit  or  consideration  in  connection  with  any 
work  which  he  is  engaged  to  design  or  to  superintend,  or  in 
connection  with  any  professional   business   which   may  be   en- 
trusted to  him. 

3.  To  neglect  informing  his  clients  of  any  business  connections, 
interests  or  circumstances  which  may  tfe  deemed  as  influencing 
his  judgment  or  the  quality  of  his  services  to  his  clients. 

4.  To  receive  directly  or  indirectly  any  royalty,  gratuity,  or 
commission  on  any  patented  or  protected  article  or  process  used 
in  work  upon  which  he  is  retained  by  his  clients,  unless  and  until 
receipt  of  such  royalty,  gratuity  or  commission  has  been  author- 
ized in  writing  by  his  clients. 

5.  To    offer    commissions    or    otherwise    improperly    solicit 
professional  work  either  directly  or  by  an  agent. 

6.  To  attempt  to  injure  falsely  or  maliciously,   directly   or 
indirectly,  the  professional  reputation,  prospects  or  business  of 
a  fellow  engineer. 

7.  To  accept  employment  by  a  client  while  the  claim  for  com- 
pensation or  damages,  or  both,  of  a  fellow  engineer  previously 
employed  by  the  same  client  and  whose  employment  has  been 
terminated,  remains  unsatisfied,  or  until  such  claim  has  been 
referred  to  arbitration,  or  issue  has  been  joined  at  law  or  unless 
the  engineer  previously  employed  has  neglected  to  press  his 
claim  legally. 

8.  To  attempt  to  supplant  a  fellow  engineer  after  definite 
steps  have  been  taken  toward  his  employment. 

9.  To  compete  with  a  fellow  engineer  for  employment  on  the 
basis  of  professional  charges  by  reducing  his  usual  charges  and 
attempting  to   underbid    after   being  informed  of  the  charges 
named  by  his  competitor. 

10.  To  accept  any  engagement  to  review  the  work  of  a  fellow 
engineer  for  the  same -client,  except  with  the  knowledge  and 
consent  of  such  engineer,  or  unless  the  connection  of  such  engineer 
with  the  work  has  been  terminated. 

Schedule  of  Fees. — As  a  general  guide  in  determining  the  fees 
for  professional  services,  The  American  Institute  of  Consulting 
Engineers  recognizes  the  propriety  of  charging  a  per  diem  rate,  a 
fixed  sum,  or  a  percentage  on  the  cost  of  work  as  follows: 

Per  Diem  Rate. — 1.  Charges  for  consultations,  reports  and 
opinions  should  vary  according  to  the  character,  magnitude  or 


ENGINEERS  AND  THEIR  SERVICES  9 

importance  of  the  work  or  subject  involved,  and  according  to 
the  experience  and  reputation  of  the  individual  engineer  from 
$100  per  day  to  a  higher  figure,  and  in  addition  where  expert 
testimony  is  required,  or  where  otherwise  conditions  warrant 
so  doing,  a  retainer  varying  from  $250  to  $1000  and  upward. 
An  additional  charge  should  be  made  for  all  actual  expenses  such 
as  traveling  and  general  office  expense  and  field  assistants  and 
materials,  with  a  suitable  allowance  for  indeterminate  items. 
In  some  cases  six  hours  of  actual  work  should  be  considered  one 
day,  except  that  while  absent  from  the  home  city  each  day  of 
twenty-four  hours  or  part  thereof,  shall  be  considered  one  day, 
irrespective  of  the  actual  hours  of  time  devoted  to  the  case. 

Fixed  Sum.— 2.  A  fixed  total  sum  for  above-mentioned  services 
may  be  agreed  on  in  lieu  of  per  diem  charges.  A  fixed  sum  may 
also  be  charged  for  a  portion  or  all  of  the  items  of  preliminary 
survey,  studies,  examinations,  reports,  detail  plans,  specifications, 
and  supervision,  including  all  the  expenses  above  recited  under 
per  diem  rate. 

Percentage  on  the  Cost  of  Work. — 3.  For  preliminary  surveys 
studies  and  reports  on  original  projects,  or  for  examination  and 
report  on  projects  prepared  by  another  engineer,  including  in 
both  cases  all  expenses  of  every  nature  except  those  that  may 
be  specifically  omitted  by  agreement — from  1J  per  cent,  to  3 
per  cent,  on  the  estimated  cost  of  the  work. 

4.  For  the  preliminary  stage  (No.  3)  and  in  addition  thereto 
detail  plans  and  specifications  for  construction,   including  all 
expenses  of  every  nature  except  those  that  may  be  specifically 
omitted   by  agreement — from  2J  per  cent,  to  5  per  cent,   on 
the  estimated  cost  of  the  work. 

5.  For  the  preliminary  and  middle  stages  (No.  3)  and  (No.  4) 
and  in  addition  thereto  general  supervision  during  construction, 
including  all  expenses  of  every  nature  except  those  that  may  be 
specifically  omitted  by   agreement — 5  per  cent.,  but   more  for 
work  costing  comparatively  small  amounts,  and  from  4  per  cent, 
to  5  per  cent,  where  the  amount  involved  is  considerable. 

6.  For  full  professional  services  (3),  (4)  and  (5)  and  manage- 
ment, including  the  awarding  of  contracts,   and  including  all 
expenses  of  every  nature  except  those  that  may  be  specifically 
omitted  by  agreement — 10  per  cent.,  but  more  for  work  costing 
comparatively  small  amounts,  and  6  per  cent,  to  10  per  cent, 
where  the  amount  involved  is  considerable. 


10       ENGINEERING  OF  SHOPS  AND  FACTORIES 

7.  When  desired,  the  percentage  basis  may  be  adopted  for 
one  or  more  stages,  supplemented  by  a  daily  or  monthly  charge 
or  fixed  sum  for  the  remaining  stage  or  stages. 

General  Provisions. — 8.  The  period  of  time  should  be  design- 
ated during  which  the  agreed  percentages  and  daily  or  monthly 
charges  or  fixed  sum  shall  apply  and  beyond  which  period  an 
additional  charge  shall  be  made. 

9.  The  percentages  are  to  be  computed  on  the  entire  cost  of 
the  complete  work  or  upon  the  estimated  cost  pending  execution 
or  completion. 

10.  Payments  shall  be  made  to  the  engineer  from  time  to  time 
in  proportion  to  the  amount  of  work  done. 

11.  When   alterations   or   additions   are   made   to   contracts, 
drawings   or   specifications,   or   when   services   are   required   in 
connection    with    negotiations,    legal    proceedings,    failure    of 
contractors,  franchises  or  right  of  way,  a  charge  based  upon  the 
time  and  trouble  involved  shall  be  made  in  addition  to  the 
percentage  fee  agreed  upon. 

Contract  between  Engineer  and  Owner. — The  following  blank 
form  of  contract  is  taken  from  Kidder's  Architects'  Pocket  Book 
with  slight  modifications,  and  will  be  found  convenient. 

Contract  between Engineer, 

and Owner. 

For  a  compensation  of ,  the  engineer  proposes 

to  furnish  preliminary  sketches,  contract,  working  drawings  and 
specifications,  detail  drawings  and.  general  superintendence  of 

building  operations,  and  also  to  audit  all  accounts,  for  a 

to  be  erected  for ,  at 

Terms  of  payment  to  be  as  follows:  Two-tenths  when  the 
preliminary  sketches  are  completed;  three-tenths  when  the 
drawings  and  specifications  are  ready  for  letting  contracts; 

thereafter  at  the  rate  of per  cent,  upon  each  certificate 

due  to  the  contractor. 

If  work  upon  the  building  is  postponed  or  abandoned,  the 
compensation  for  the  work  done  by  the  engineer  is  to  bear  such 
relation  to  the  compensation  for  the  entire  work  as  determined 
by  the  published  schedule  of  fees  previously  given. 

In  all  transactions  between  the  owner  and  contractor,  the 
engineer  is  to  act  as  the  owner's  agent,  and  his  duties  and  liabil- 
ities in  this  connection  are  to  be  those  of  agent  only. 


ENGINEERS  AND  THEIR  SERVICES  11 

A  representative  of  the  engineer  will  make  visits  to  the  building 
for  the  purpose  of  general  superintendence,  of  such  frequency  and 
duration  as,  in  the  engineer's  judgment,  will  suffice  or  may  be 
necessary  to  fully  instruct  contractors,  pass  upon  the  merits  of 
material  and  workmanship,  and  maintain  an  effective  working 
organization  of  the  several  contractors  engaged  upon  the 
structure. 

The  engineers  will  demand  of  the  contractors  proper  correction 
and  remedy  of  all  defects  discovered  in  their  work,  and  will 
assist  the  owner  in  enforcing  the  terms  of  the  contracts;  but  the 
engineer's  superintendence  shall  not  include  liability  or  respon- 
sibility for  any  breach  of  contract  by  the  contractors. 

The  amount  of  the  engineer's  compensation  is  to  be  reckoned 
upon  the  total  cost  of  the  building,  including  all  stationary 
fixtures. 

Drawings  and  specifications  are  instruments  of  service,  and 
as  such  are  to  remain  the  property  of  the  engineer. 

Approved  and  accepted, 

Chicago,  June  1st,  1912.         By 

Engineer. 

Owner. 

A  shorter  form  of  contract,  which  will  in  many  cases  be  quite 
satisfactory  is  as  follows: 

Short  Form  of  Contract. — The  undersigned  hereby  agrees  to 

employ    Engineer,   to    furnish   scale    drawings, 

details,  specifications,  and  to  do  the  superintendence  for  a  build- 
ing at ,  at  the  rate  of per  cent,  com- 
mission for  drawings,  and  per  cent,  commission  for 

superintendence,  the  commission  to  be  based  on  the  lowest  bid 
or  bids  received  on  the  work  as  an  entirety.  Furthermore, 
that  in  event  of  abandonment  after  preliminary  sketch  has 

been   submitted,  will   pay   said   Engineers   the  sum   of 

Dollars  ($ )  on  demand  for  said  sketches,  and 

if  work  is  abandoned  after  scale  drawings,  details  and  specifica- 
tions are  completed, will  pay  the  full per  cent. 

of  lowest  estimate  as  an  entirety. 
Signed 

Owner. 

The  above  contract  is  hereby  accepted  by 

Engineer. 


CHAPTER  II 
MANUFACTURING  DISTRICT 

Selection  of  Manufacturing  District. — The  selection  of  the 
most  advantageous  district  is  in  some  respects  one  of  the  most 
important  features  of  shop  economics,  for  if  buildings  are 
wrongly  placed,  they  must  continue  operation  under  serious 
handicap,  or  else  meet  the  alternative  of  removal.  The  con- 
siderations which  are  of  chief  importance  in  selecting  a  district 
are  as  follows: 

1.  Place — city  or  suburb. 

2.  Cost  of  land  and  ground  area  required. 

3.  Labor  supply  and  wages. 

4.  Nearness  to  raw  materials  and  fuel. 

5.  Nearness  to  source  of  power. 

6.  Shipping  facilities. 

7.  Climate. 

8.  Market  for  manufactured  products. 

It  is  rarely  possible  to  find  a  place  having  all  the  desired 
requirements,  and  the  best  that  can  be  done  after  weighing  the 
pros  and  cons  of  several  possible  districts  is  to  select  the  one 
which  has  the  greatest  number  of  advantages. 

1.  When  contemplating  a  site  in  any  region,  a  choice  must  first 
be  made  between  large  cities  and  smaller  ones,  or  a  suburban  or 
country  district.  The  advantage  of  a  large  city  is  that  the 
proposed  business  is  more  closely  in  touch  with  other  business; 
that  additional  help  can  be  quickly  found  when  ne.eded;  that  a 
city  enterprise  is  more  easily  financed  than  a  rural  one,  and  that 
shops  so  located  become  more  quickly  known  and  are  in  them- 
selves an  effective  advertisement. 

Some  of  the  disadvantages  of  a  large  city  for  manufacturing- 
are  the  high  cost  of  land  and  necessity  in  most  cases  of  using 
multi-story  buildings;  the  smaller  chance  for  expansion;  the 
transient  habits  of  city  workmen;  the  difficulty  of  keeping  a 
permanent  force;  the  lack  of  personal  touch  between  employer 
and  employee;  greater  difficulty  from  trade  unions;  higher  cost 

12 


MANUFACTURING  DISTRICT  13 

of  living;  the  imposition  in  many  cases  of  city  building  laws;  and 
altogether  the  difficulty  in  finding  ideal  conditions.  Taxes  in  a 
city  may  amount  to  $40  or  $50  per  year  for  each  employee, 
while  in  the  country  or  in  a  suburb  they  may  not  exceed  $5  per 
year. 

Small  cities  or  suburban  districts  are  usually  preferred,  as 
workmen  are  not  only  more  comfortable  and  contented  in  such 
places  but  they  are  able  to  do  more  and  better  work  in  good  light, 
pure  air  and  congenial  surroundings.  The  most  attractive 
districts  for  manufacturing  are  often  within  a  mile  of  some  small 
city  which  has  a  population  of  not  less  than  about  25,000,  excel- 
lent examples  being  the  National  Cash  Register  Works  (Fig.  2)  at 
Dayton,  Ohio,  and  the  Allis-Chalmers  Plant  near  Milwaukee, 
Wis.  In  such  places  unoccupied  land  is  abundant  and  can 


FIG.  2. — National  Cash  Register  Works,  Dayton,  Ohio. 

usually  be  purchased  at  prices  of  $200  to  $500  per  acre.  A  dis- 
trict should  be  chosen  near  one  or  more  lines  of  railroad,  and 
adjoining  some  good  water  supply  such  as  a  lake  or  river.  If  a 
trolley  line  is  not  already  built  along  the  highway,  the  presence 
of  a  manufactory  will  very  soon  bring  the  desired  rail  connection 
to  the  adjoining  town,  so  that  workmen  may  ride  or  walk  to  and 
from  their  work  as  they  prefer.  There  is  usually  a  slight  dis- 
advantage from  being  outside  the  city  limits  in  that  insurance 
rates  are  about  25  cents  per  $100  more  than  within  reach  of  city 
hydrants.  When  placed  parallel  with  and  far  enough  away 
from  a  main  line  of  railroad,  buildings  with  signs  above  them 
large  enough  to  be  easily  seen  and  read  by  people  in  passing 
trains,  are  in  themselves  very  effective  advertising.  When  thus 
located  on  main  lines  of  railway  between  important  towns  or 


14       ENGINEERING  OF  SHOPS  AND  FACTORIES 

large  cities,  this  kind  of  display  is  very  impressive,  especially 
when  buildings  are  new  and  attractive. 

A  rural  or  country  district,  remote  from  towns  or  cities,  is 
desirable  only  in  rare  instances  where  other  advantages  are  great 
and  evident,  such  as  the  presence  of  fuel  beds,  raw  material  or 
power.  To  avoid  heavy  freight  charges,  clay  industries  and 
brick  yards  must  usually  be  placed  wl^re  the  clay  is  found,  or 
to  save  transmission  expense,  the  presence  of  natural  water 
power  may  sometimes  be  reason  enough  for  building  the  plant 
away  from  a  town  but  near  the  water  power.  When  too  far 
from  town,  the  company  must  invest  extra  money  in  houses  for 
their  workmen,  which  has  been  done  in  many  cases,  such  as  at 
the  plants  of  the  Maryland  Steel  Company,  and  some  of  the 
American  Bridge  Company's  plants.  These  houses  should  be 
comfortable  and  commodious,  and  in  keeping  with  other  accom- 
modations for  employees  in  modern  industries.  Congenial 
surroundings  for  workmen  are  not  a  philanthropic  measure  on 
the  part  of  employers,  but  rather  an  assistance  in  securing  and 
retaining  a  proficient  class  of  operatives. 

After  choosing  between  large  and  small  cities,  or  one  of  their 
suburbs,  the  other  matters  outlined  at  the  beginning  of  this 
chapter  may  be  taken  up  in  order. 

2.  The  three  most  important  considerations  in  selecting  a 
manufacturing  district  are  the  cost  of  land  and  presence  of  labor 
and  raw  materials,  the  first  of  these  frequently  being  the  most 
important.  If  too  much  money  is  invested  in  the  land,  the  rent, 
taxes  and  interest  on  the  investment  may  be  such  a  heavy  charge 
against  the  business  as  to  seriously  reduce  the  possible  dividends. 
In  large  cities,  land  is  often  more  valuable  than  the  buildings  on 
it,  and  the  money  which  might  be  received  by  selling  the  city 
land  would  pay  for  both  land  and  new  buildings  in  a  less  expen- 
sive district.  Certain  lines  of  industry  require  so  much  ground 
for  their  one-story  shops,  and  for  yards  and  tracks,  that  city 
land  may  not  only  be  too  expensive,  but  a  block  of  the  required 
size  may  not  be  obtainable.  Car  shops,  structural  works,  and 
nearly  all  kinds  of  metal  working  shopa  come  under  this  heading. 

In  the  business  district  of  New  York  City,  lots  sell  for  $100  to 
$600  per  square  foot,  and  in  the  central  part  of  Chicago  and 
Boston,  from  $90  to  $100  p*er  square  foot.  In  Chicago,  land 
constitutes  55  per  cent,  of  the  whole  value,  and  improvements 
only  45  per  cent.,  while  in  Boston  the  land  values  are  nearly  50 


MANUFACTURING  DISTRICT  15 

per  cent,  more  than  improvements.  The  land  in  Cleveland,  as 
a  whole,  is  valued  at  40  per  cent,  more  than  all  the  buildings, 
and  similar  proportions  apply  elsewhere. 

3.  The   need   of   abundant   labor   is   so   important   that   the 
tendency  is  to  place  new  works  in  the  vicinity  of  others  making 
the  same  kind,  or  similar  goods.     Skilled  labor  for  iron  works  is 
abundant  in  such  cities  as  Cleveland  and  Pittsburg;  for  cotton 
mills,  in  Massachusetts  and  Rhode  Island;  for  packing  houses, 
in  such  places  as  Chicago  and  Kansas  City;  and  for  automobile 
factories,  at  Detroit  and  other  cities  in  Michigan.     The  prevailing 
rate  of  wages  also  varies  according  to  location,  being  lower  in  the 
Southern  States  and  most  parts  of  Canada  than  in  the  Eastern 
and  Middle  States,  or  on  the  Pacific  Coast.     As  the  cost  of  labor 
is  continuous  and  is  sometimes  half  the  operating  expense,  a 
small  difference  in  the  rates  paid  is  likely  to  be  quite  large  in  the 
aggregate.     A  less  cost  of  labor  and  building  material  may  also 
cause  an  important  reduction  in  the  cost  of  building  the  plant. 

4.  When  a  large  amount  of  raw  material  and  fuel  is  used,  it  is 
desirable  to  select  a  district  near  to  one  or  both  of  them,  where 
the  total  cost  of  all  transportation  charges  will  be  a  minimum. 
Nearness  to  materials  is,  therefore,  of  most  importance  in  plants 
with  heavy  products,  and  the  need  of  such  a  location  decreases 
with  the  volume  of  freight.     For  light  manufacture,  where  the 
cost  of  products  depends  chiefly  on  the  labor  expended  on  them, 
rather  than  upon  their  volume  or  weight,  nearness  to  supplies  is 
of  little  importance. 

5.  Nearness  to  the  source  of  power  is  a  consideration  when 
direct  water  power  and  turbines  are  used.     This  kind  of  power, 
however,  is  not  so  much  favored  as  formerly,  for  it  can  better  be 
used  now  for  generating  electrical   currents,  which  are   more 
easily  transmitted.     Thirty  years  ago,  water  power  sites  were 
at  a  premium,  and  the  growth  and  business  of  many  cities  such 
as  Lawrence  and  Lowell,  Mass,  were  largely  due  to  the  presence 
of  such  power. 

6.  It  is  an  advantage  to  have  at  least  two  competing  lines  of 
railway  serving  the  plant  if  the  amount  of  shipping  is  large,  and 
water  transpoftage  may  also  be  convenient,  as,  in  most  cases, 
freight  by  water  is  cheaper  than  by  rail.     Large  cities  with 
many  lines  of  railroad,  have  the  greatest  shipping  facilities,  espe- 
cially those  on  the  Great  Lakes  and  on  the  sea  coast.     For 
light  manufactures,  where  labor  is  the  chief  item  of  cost,  and 


16       ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  amounts  of  shipping  is  small,  it  may  be  permissible  in  some 
instances  to  place  the  plant  away  from  main  lines  of  railway  where 
other  advantages,  such  as  cheap  land,  may  be  found. 

7.  Climate  is  sometimes  an  important  consideration  in  selecting 
a  manufacturing  district,  as  places  which  are  known  to  be  subject 
to  cyclones,  earthquakes,  and  violent  storms  are  in  this  respect 
undesirable.     Extreme    temperatures  jof    heat    and    cold,    the 
depth  to  which  frost  penetrates,  the  amount  of  snow  and  rain, 
all  affect  operation  to  some  extent.     It  is  well  known  that  a  cold 
and  bracing  climate  is  invigorating,  and  for  this  reason,  northern 
districts  are  sometimes  preferred;  northern  races  such  as  the 
Highlanders,   Scandinavians    and  Canadians  are  usually  more 
energetic  and  progressive  than  the  residents  of  warm  countries, 
such  as  Spain  and  Italy. 

8.  The  market  for  products  will  also  affect  the  selection  of  a 
district.     If  goods  are  chiefly  for  export  to  Europe  and  other 
eastern   and   southern   countries,   some  places  on  the   Atlantic 
seaboard  would  probably  be  the  best;  whereas,  if  products  are 
mostly  for  export  to  Japan  and  China,  the  Pacific  coast  would  be 
preferred.     Manufacturers  of  agricultural  implements  find  the 
Central  States  adjoining  the  grain  belt  to  be  the  most  convenient, 
and  many  such  industries  may  be  found  in  such  cities  as  Chicago, 
Kansas  City,  Omaha,   and  in  some  parts  of  Western  Canada. 

Selection  of  Building  Lot. — After  deciding  upon  the  district  or 
region  which  is  best  suited  for  the  proposed  industry,  some  one 
building  lot  must  be  selected  from  several  possible  ones.  In 
choosing  a  district,  it  will  be  impossible  to  find  a  block  with  all 
the  desired  advantages.  Features  to  be  considered  are:  (1) 
cost,  (2)  grade,  (3)  water  supply,  (4)  drainage,  (5)  foundations, 
and  (6)  approaches.  There  must  also  be  facilities  for  heating, 
ventilating  and  lighting  the  building,  and  for  development  or 
application  of  power,  as  well  as  for  the  handling  of  materials. 
The  selection  of  a  site  may  also  be  affected  to  some  extent  by 
the  need  of  fire  protection  and  the  degree  of  permanence  desired. 

The  first  cost  is  really  of  less  importance  than  expenses,  such 
as  wages  and  freight,  that  are  continuous.  A  lot  which  will  save 
the  owner  $1000  per  year  by  its  better  facilities  for  handling, 
shipping  or  storing  goods,  is  worth,  at  5  per  cent,  interest,  $20,000 
more  to  him  than  another  lot  which  cannot  make  such  saving. 
Therefore,  if  the  owner  can  buy  the  better  lot  at  anything  less 
than  $20,000  more  than  the  other,  he  is  exercising  economy. 


MANUFACTURING  DISTRICT  17 

The  grade  of  lot  should  be  level  or  nearly  so,  the  preference 
usually  being  for  a  slope  of  about  one-half  of  1  per  cent,  in  the 
direction  that  goods  pass  in  the  course  of  manufacture.  Some 
low  ground  is  not  objectionable,  as  it  can,  perhaps,  be  used  for 
dumping  ashes  or  other  refuse.  Hillsides  are  rarely  desirable, 
unless  for  gravity  transportation,  such  as  at  mine  shafts  or  stone 
quarries  where  the  descending  loaded  car  hauls  the  empty  one  up 
the  grade. 

A  supply  of  fresh  water  is  needed  for  boiler  feed,  sanitation,  etc., 
and  soft  water  is  preferable  to  that  containing  lime  or  salt.  In 
cities  it  can  be  taken  from  the  street  mains  at  a  cost  of  $2  to  $4 
per  year  for  each  employee,  which  in  a  plant  with  500  people  might 
amount  to  $1000  or  more  per  year.  In  this  item  alone,  a  lot 
with  a  natural  supply  would,  at  5  per  cent.,  be  worth  $20,000  to 
$40,000  more  to  the  owner  than  another  one  without  it. 

The  lot  should  be  high  enough  above  some  adjoining  area  or 
channel  that  it  will  be  well  drained,  a  bed  of  gravel  and  sand 
being  the  best  for  this  purpose.  This  sub-strata  is  also  a  good 
one  for  foundations,  especially  in  plants  where  heavy  loads  must 
be  sustained.  Quicksand  must  always  be  avoided,  as  it  is  too 
uncertain  for  foundations  of  any  kind,  except  in  cases  of  extreme 
necessity. 

The  roads  or  approaches  to  the  plant  should  be  put  in  good 
condition.  Brick  is  an  excellent  paving  for  driveways  and  walks, 
as  it  is  easily  drained,  and  horses  find  a  more  secure  foothold  than 
on  a  smooth  pavement.  Cobble  stones,  while  suitable  for  draft 
horses,  are  too  uncomfortable  for  pedestrians. 

After  carefully  considering  the  advantages  of  several  sites, 
and  selecting  the  one  most  suitable  for  the  purpose,  a  survey 
should  be  made  by  a  local  surveyor,  who  has  access  to  other 
property  maps,  lines  and  grades,  and  a  drawing  should  be  plotted, 
showing  adjoining  property  lines,  buildings,  roads,  water  courses, 
gas  and  water  pipes,  with  elevations  and  grade,  and  all  other 
data  which  will  be  of  interest  to  the  engineer  and  owner. 

The  choice  of  lot  may  sometimes  be  postponed  until  after  the 
arrangement  of  departments  and  buildings,  and  the  total  re- 
quired property  areas  are  determined.  If  several  lots  of  ground 
are  under  consideration,  a  good  method  of  procedure  is  to  reject 
successively  the  least  desirable  ones,  when  finally  the  best  one 
will  remain. 


CHAPTER  III 
ECONOMICS  OF  FACTORY  CONSTRUCTION 

Before  beginning  the  detail  drawings,  the  following  matters  of 
shop  economics  must  be  carefully  considered,  and  about  in  the 
order  as  given: 

1.  Proposed  methods  of  manufacture. 

2.  Proposed  methods  of  management. 

3.  Collection  of  data  relative  to  other  similar  plants. 

4.  Schedule  of  machines  which  must  be  housed. 

5.  Arrangement  of  machines. 

6.  Area  and  elevation  of  floors  for  each  department. 

7.  Receiving  and  shipping  facilities. 

8.  Provision  for  extension. 

9.  Arrangement  of  departments. 

10.  Preparatory  design  of  buildings. 

11.  Approximate  cost  estimates. 

Each  of  these  subjects  will  be  considered  in  the  following 
pages,  and  their  relative  importance  will  depend  somewhat  on  the 
nature  of  the  goods  produced. 

1.  Proposed  Methods  of  Manufacture. — One  of  the  first  duties 
of  an  industrial  engineer  when  undertaking  the  planning  of  a 
manufacturing  plant,  is  to  inform  himself  thoroughly  in  reference 
to  the  methods  of  manufacture  and  management  to  be  used  in 
the  shops  after  their  completion.  The  owners  will  have  first 
estimated  the  probable  amount  of  goods  that  can  be  sold  or  put 
on  the  market  per  year,  and  from  this  estimate,  reduced  to  a 
money  value,  an  approximation  can  be  made  of  the  prospective 
profits.  Considering  these  profits  as  interest  on  an  investment, 
the  expenditure  that  is  permissible  can  readily  be  determined. 
For  instance,  consider  that  goods  to  the  value  of  $500,000  could 
be  marketed  annually  with  a  profit  of  20  per  cent,  or  $100,000. 
This  amount  of  profit  is  10  per  cent,  interest  or  dividend  on  an 
investment  of  $1,000,000.  With  this  limiting  value  and  the 
estimate  of  goods  which  can  be  marketed  annually,  with  due 
allowance  for  growth  or  expansion,  an  approximation  can  be 
made  of  the  required  capacity  of  the  new  plant. 

18 


ECONOMICS  OF  FACTORY  CONSTRUCTION       19 

All  these  matters  are  most  familiar  to  the  factory  owner,  and 
he  must  inform  the  engineer  of  his  requirements.  If  the  buildings 
are  extensions  to  those  already  in  use,  he  must  explain  for  what 
departments  the  new  ones  are  intended  and  the  special  require- 
ments of  those  departments  as  well  as  their  probable  output. 
All  of  these  matters  may  be  studied  personally  by  the  owner 
when  the  plant  is  small,  but  in  larger  works  one  or  more  persons 
are  frequently  employed,  each  of  whom  makes  it  his  special  duty 
to  investigate  matters  pertaining  to  shop  equipment,  arrange- 
ment, production  methods  and  management,  and  to  this  indi- 
vidual, whether  executive  or  owner,  the  engineer  must  look  for 
data  in  reference  to  the  proposed  methods  of  manufacture. 
Such  study  is  indeed,  in  many  plants,  one  of  the  most  important 
duties  in  connection  with  the  whole  enterprise,  for  it  involves 
much  research,  and  investigation  of  ways  and  means  used  by 
other  shops  manufacturing  the  same  or  similar  goods.  In  order 
to  secure  such  information  some  managers  even  resort  to  the 
questionable  method  of  advertising  important  positions  vacant, 
for  the  purpose  of  securing  applications  from  men  employed  in 
similar  shops,  not  that  assistance  is  needed,  but  that  suggestions 
from  these  men  are  more  easily  obtained  when  a  prospective 
position  is  in  view.  The  policy  of  the  officer  in  charge  of 
manufacturing  methods  is  to  secure  new  ideas  from  any  or  all 
sources,  whether  from  the  humblest  employee  of  his  own  factory 
or  from  important  officials  of  competing  companies.  Some  shops 
us.e  the  "suggestion  system/7  offering  premiums  to  any  who 
furnish  valuable  ideas  which  will  aid  in  production,  or  diminish 
the  cost,  and  for  this  purpose  letter  boxes  are  placed  about  the 
works,  in  which  employees  may  drop  written  memoranda  which 
may  be  valuable  to  the  management.  Whenever  any  of  these 
suggestions  are  put  into  use,  the  person  contributing  it  is  duly 
repaid.  Profits  in  manufacturing  plants  usually  depend  as  much 
upon  the  low  cost  of  production,  as  they  do  in  retail  establish- 
ments on  careful  buying,  because  in  both  lines  of  business,  selling 
prices  are  fixed  by  those  of  competitors.  Hence,  every  sugges- 
tion or  improved  method  which  will  reduce  the  production  cost 
is  a  proportionate  gain. 

The  matters  referred  to  above  are  familiar  to  plant  owners 
and  managers,  such  knowledge  being  part  of  their  stock  in  trade, 
and  any  data  which  the  engineer  needs  should  be  supplied  to  him. 
He  should  make  note  of  the  owners'  ideas  and  requirements,  and 


20       ENGINEERING  OF  SHOPS  AND  FACTORIES 

personally  inspect  the  old  shops  and  similar  ones,  to  better 
acquaint  himself  with  the  needs  of  the  new  plant.  Matters 
pertaining  exclusively  to  building  construction  and  methods  of 
lighting,  heating,  ventilating,  etc.,  are  usually  better  understood 
by  the  engineer  or  architect  than  by  any  one  else,  though  even 
in  these  matters,  the  owners  will  usually  have  their  preferences. 
For  the  manufacture  of  small  goods  \0iere  labor  rather  than  ma- 
terials is  the  largest  element,  buildings  of  rectangular  plan  in 
several  stories  are  usually  preferable,  with  the  advantage  that  a 
change  is  more  easily  made  in  the  arrangement  of  ^machinery  or 
departments,  but  shops  for  the  manufacture  of  larger  goods, 
such  as  heavy  machinery,  must  usually  be  of  some  special  form. 

2.  Methods  of  Management. — During  the  last  few  years,  great 
progress  has  been  made  in  methods  of  shop  management,  and 
several  valuable  books  have  been  written  on  the  subject.     For 
this  reason,  and  with  the  prospect  of  further  improvements  in  this 
direction,  much  foresight  is  needed  when  making  preparatory 
plans.     As  far  as  possible,  it  is  better  to  arrange  the  plant  so  the 
administration   methods   can   be   changed   if   necessary.     Shop 
offices,  tool  rooms  and  other  enclosures  should  therefore  be  made 
with  partitions  that  are  removable,  and  benches,  storage  cases 
and  other  furnishing  should  be  placed  and  installed  so  they  can  be 
easily  changed.     The  use  and  position  of  time  clocks  may  de- 
termine the  location  of  doorways  for  employees  and  passageways 
through  the  shops.     Any  matters  of  this  kind  relating  to  the 
subsequent  management,  may  affect  the  design,   and  on  these 
subjects  the  engineer  should  be  informed. 

3.  Particulars  of  Similar  Plants. — Before  going  further  with 
plans,  the  engineer  should  collect  and  compile  data  relating  to 
other  plants  of  the  same  kind,  or  similar  ones.     This  is  most 
easily  obtained  from  drawings  and  reports  in  trade  journals,  as 
personal  examination  of  buildings  is  usually  bewildering  from 
their  complexity,  of  detail.     A  personal  visit  may,  however,  be 
beneficial  after  drawings  have  been  examined,  or  when  these  are 
not  obtainable,  and  on  such  excursions,  a  small  camera  is  valuable. 
Very  little  data  of  the  kind  is  now  available  without  original 
research,  and  it  is  for  this  reason  that  engineering  companies  who 
have  collected  and  preserved  such  information,  are  able  to  pre- 
pare plans  more  quickly  than  others  who  are  without  it.     If 
the  new  buildings  are  additions  to  old  ones,  the  latter  should  be 
carefully  studied.     Floor  space,  capacity,  number  of  employees, 


ECONOMICS  OF  FACTORY  CONSTRUCTION       21 

daily  or  monthly  production,  arrangement  of  contents,  etc., 
should  be  examined  and  noted,  and  the  results  analyzed,  to 
such  ready  reference  units  as  floor  space  and  cubic  contents  of 
shop  per  unit  of  product,  or  per  employee.  The  cost  of  buildings, 
amount  of  power,  etc.,  should  all  be  noted,  and  these  data  and 
analyses  should  be  preserved  for  future  reference. 

New  buildings  should  not  necessarily  be  just  like  other  ones 
manufacturing  similar  products,  .and  features  should  not  be 
copied  without  knowing  fully  the  reason  for  their  presence,  for  in 
the  other  building  there  may  have  been  some  special  need  for 
these  features,  which  does  not  exist  in  the  new  one.  Caution 
must,  therefore,  be  used  in  these  matters.  Data  of  the  kind 
gleaned  from  journals  or  drawings,  can  well  be  supplemented 
by  practical  suggestions  from  foremen  or  employees,  who  are 
often  more  familiar  than  engineers  with  practical  shop  needs. 
If  an  industrial  engineer  is  not  in  possession  of  information  of  this 
kind,  several  months  might  profitably  be  spent  in  investigation 
and  research,  and  owners  are  frequently  willing  to  wait,  in  order 
to  have  a  more  efficient  plant.  In  other  cases,  when  new  pro- 
jects are  undertaken,  owners  prefer  to  see  results  at  once,  even  at 
a  somewhat  greater  initial  cost,  in  order  to  have  their  goods  on 
the  market  and  earning  dividends.  Industrial  engineers  are 
therefore  wise  to  provide  themselves  beforehand  with  as  much 
data  as  possible,  pertaining  to  other  plants.  When  facts  must 
be  collected  for  a  particular  industry,  several  men  may  be 
employed  in  research,  each  one  taking  a  special  part,  and  the 
whole  may  afterward  be  assembled  and  arranged  by  one  person. 
Uniform  methods  and  units  must  be  used,  in  order  that  the  analy- 
sis may  be  accurate.  For  example,  building  areas  should  be 
computed  either  from  their  inside  dimensions  in  all  cases,  or 
from  their  outside.  While  studying  other  plants,  especial  note 
should  be  made  of  their  efficiency,  operating  and  maintenance 
expense,  cost,  type  of  construction,  and  provision  for  extension, 
so  that  all  features  of  special  value  may  be  incorporated  in  the 
new  plans. 

4.  Schedule  of  Machinery. — After  collecting  data  relating  to 
the  proposed  methods  of  manufacture  and  management,  and  to 
other  similar  industries,  initial  work  on  the  new  plant  may  begin. 
It  is  better  to  start  with  a  small  plan  showing  only  the  essentials 
without  detail,  and  to  develop  it  as  investigation  progresses. 
By  this  method  the  final  result  should  be  logical. 


22       ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  schedule  of  machines  to  be  used  in  the  new  shops  will 
depend  upon  the  proposed  capacity  or  output,  and  the  list  should 
either  be  made  by  the  owner  or  manager,  or  should  be  examined 
and  approved  by  him.  The  machines  may  all  be  new,  or,  if 
the  buildings  are  extensions  of  former  ones,  some  old  ones  may 
be  utilized.  Those  of  standard  make  are  usually  the  cheapest 
and  best,  because  improvements  have  been  made  on  them  as 
found  desirable  from  experience.  If  the  regulations  of  trade 
unions  should  in  any  case,  prevent  the  use  of  certain  machines, 
others  of  equal  utility  can  perhaps  be  substituted.  Machines 
should  as  far  as  possible,  be  used  instead  of  manual  labor,  that 
operating  expense  may  be  kept  at  a  minimum.  The  saving  of 
$100  per  year  in  wages  will  generally  warrant  an  investment  of 
about  $2000  in  machinery. 

It  is  seldom  economical  to  manufacture  light  and  heavy  goods 
in  the  same  shops,  or  articles  which  differ  greatly  from  each  other, 
because  some  of  the  machines  may  then  be  idle  much  of  the 
time.  A  separate  schedule  of  machines  should  be  made  for 
each  department. 

5.  Arrangement  of  Machines. — In  arranging  the  machinery  in 
each  department  of  a  shop,  efficiency  should  be  the  chief  consider- 
ation. The  course  of  travel  taken  by  goods  in  process  of  manu- 
facture should  first  be  studied  and  established — a  duty  which 
should  be  performed  or  directed  by  the  owner  or  manager,  and 
this  course  should  always  be  either  forward  or  zig-zag  back  and 
forth  over  the  shop  floor,  but  never  backward.  When  the 
sequence  of  operations  has  been  established,  the  machines  may 
then  be  placed  accordingly,  passageways  being  left  where 
needed.  The  arrangement  should  be  such  as  to  require  the 
least  total  amount  of  travel  and  handling,  and  provision  should 
be  made  for  additional  ones  when  needed  (Fig.  3) .  The  building 
laws  of  some  cities  specify  the  minimum  space  which  will  be 
allowed,  as,  for  instance,  in  Cleveland  where  each  day  worker 
must  have  not  less  than  25  sq.  ft.  of  floor  space,  and  300  cu.  ft. 
of  air,  and  each  night  worker  40  sq.  ft.  of  floor  and  480  cu.  ft. 
of  air. 

When  layouts  have  been  made  showing  the  contents  of  each 
department  arranged  to  the  best  advantage,  the  required  areas 
of  these  departments  should  be  tabulated,  open  or  uncovered 
parts  being  kept  separate  from  those  which  must  be  enclosed  or 
housed. 


ECONOMICS  OF  FACTORY  CONSTRUCTION       23 


The  most  convenient  method  of  arranging  and  locating  the 
machines  is  to  first  make  small  scale  drawings  of  each  one 
showing  the  outside  di- 
mensions of  the  base  or 
foundation,  with  the  part 
above  the  floor  in  dotted 
lines.  These  drawings 
may  either  be  made  to 
the  same  scale  as  the  floor 
plans,  or  since  drawings 
of  such  small  scale  are 
neither  easily  made  nor 
very  accurate,  they  can 
be  drawn  three  or  four 
times  larger  than  the  de- 
sired size,  and  zinc  etch- 
ings of  the  proper  reduc- 
tion made  from  the  draw- 
ings. From  these  zinc 
plates  as  many  prints 
may  be  made  as  desired, 
only  one  plate  being 
needed  for  each  kind  of 
machine,  even  though 
several  duplicate  ones 
may  be  used.  When 
zinc  etchings  are  used,  the 
drawings  may  be  so  as- 
sembled that  the  blocks 
or  plates  will  be  of  some 
convenient  size  such  as 
54  by  8  in.,  or  4  by  6 
in.,  the  cost  of  plates 
being  about  five  cents  per 
square  inch.  Small  scale 
drawings,  or  prints  from 
the  zinc  plates  may  then 
be  cut  up  and  arranged 
over  the  floor  plan  in  the 
desired  order,  and  temporarily  attached  thereto  with  pins. 
Several  alternate  arrangements  may  thus  be  made,  each  with  a 


24       ENGINEERING  OF  SHOPS  AND  FACTORIES 

new  floor  plan  and  dummies,  and  when  these  alternate  studies 
are  finished  they  may  be  compared  and  the  best  features  of  each 
selected  for  the  ultimate  arrangement. 

6.  Area  and  Elevation  of  Floor  in  each  Department. — When  the 
machines  have  been  arranged  to  produce  with  the  greatest 
efficiency,  the  total  required  area  can  then  be  determined.  If 
goods  are  handled  between  the  macMnes,  there  must  be  space 
not  only  for  storage  but  for  workmen.  The  space  should  not 
be  too  large,  for  compact  arrangement  saves  steps  and  time. 
This  principle  is  well  understood  in  house  architecture,  where 
small  kitchens  conveniently  arranged  are  usually  preferred  to 
larger  ones.  The  amount  of  space  needed  around  machines 
depends  to  some  extent  upon  the  methods  of  lifting  goods, 
whether  by  hand  or  with  hoists.  Space  must  sometimes  be 
left  for  storage  and  the  amount  will  depend  somewhat  on  condi- 
tions. Little  is  needed  when  goods  in  the  course  of  manufacture 
pass  continuously  from  one  machine  to  another.  In  other  cases 


FIG.  4. — Ford  Motor  Works,  Detroit,  Mich. 

more  storage  space  may  be  needed,  the  amount  depending  on  the 
size  of  goods  and  method  of  piling  them.  Some  space  may  be 
saved  by  storing  small  parts  on  racks  or  shelves. 

The  tabulated  floor  areas  referred  to  above,  should  show  the 
total  areas  required  in  each  department,  with  subdivisions  giving 
the  amount  of  space  in  each  case,  that  must  be  on  the  solid 
ground.  Investigation  of  this  table  will  show  the  number  of 
stories  than  can  be  used,  and  the  probable  outline  of  the  build- 
ings. Experience  shows,  that  for  cotton  mills,  four  stories  are 
usually  the  most  convenient.  Some  designers  are  so  enthusiastic 
over  single  story  shops,  as  to  specify  them  in  nearly  all  cases, 


ECONOMICS  OF  FACTORY  CONSTRUCTION       25 


but  like  many  other  comparatively  new  ideas,  the  one  story 
shop  has  frequently  been  used  without  sufficient  reason. 

The  width  of  stories  is  usually  fixed  by  the  need  of  lighting 
from  the  sides.  Those  of  modern  design  in  which  a  large  pro- 
portion of  the  exterior  walls  is  of  glass,  are  well  lighted  from  the 
side  windows  in  widths  up  to  75  ft.  or  more.  The  Ford  Motor 
Company  building  (Fig.  4)  at  Detroit,  four  stories  high,  865  ft. 
long  and  75  ft.  wide,  is  as  light  inside  as  any  old  style  building  of 
only  half  its  width. 

Adjoining  buildings,  even  though  of  different  widths,  should 
have  stories  of  the  same  height,  if  they  are  ever  to  be  connected 
by  foot  bridges.  Story  heights  for  buildings  of  different  width 
are  as  follows: 

Width  up  to  50    ft Height  of  story,  12  ft. 

Width  up  to  75    ft Height  of  story,  13  ft. 

Width  up  to  100  ft Height  of  story,  14  ft. 

7.  Receiving,  Storing  and  Shipping  Facilities. — The  im- 
portance of  these  facilities  is  evident  without  discussion.  Goods 


M 111 I 


FIG.  5. — Boiler  shops  of  the  Babcock  &  Wilcox  Co.,  Bayonne,  N.  J. 

must  be  received  at  that  part  of  the  works  where  manufacture 
commences,  and  after  passing  through  the  various  departments, 
will  be  stored  or  shipped  when  finished.  Switch  tracks  should 
branch  off  from  main  lines  with  curves  that  are  not  too  sharp  for 
standard  locomotives,  with  a  radius  never  less  than  235  ft.  A 
comparison  of  stub  end  tracks  and  circuits,  yard  "ladders",  etc., 
is  considered  in  later  pages.  Enough  sidings  and  storage  space 


26       ENGINEERING  OF  SHOPS  AND  FACTORIES 

for  raw  materials  are  needed  so  the  railway  companies  will  have 
no  reason  for  making  rental  charges  on  unloaded  cars  (Figs.  5 
and  6) .  Storage  space  should  be  ample  for  raw  materials  and 
finished  products,  as  well  as  for  the  temporary  accommodation  of 
surplus  stock  in  course  of  manufacture.  The  last  may  be  greatly 
needed  when  work  in  one  department  is  delayed  by  accident  or 
absence  of  employees,  in  which  case,  goods  from  previous  de- 
partments can  go  into  temporary  storage.  If  this  is  not  provided 


FIG.  6. — Shops  and  residence  tract,  Trafford  City,  Pa. 

some  departments  will  be  over  loaded  with  goods  while  others  will 
be  delayed.  Required  storage  space  which  can  as  well  be  out  of 
doors  should  in  the  tabulation  be  kept  separate  from  that  which 
must  be  covered.  In  small  plants,  goods  in  course  of  manufac- 
ture may  pass  in  U-shape  through  the  buildings,  so  that  track 
may  be  needed  on  only  one  side  of  the  plant,  raw  material  being 
received  at  one  end  of  the  track  platform  and  finished  goods 
shipped  from  the  other  end  (Fig.  7) . 


ECONOMICS  OF  FACTORY  CONSTRUCTION       27 


8.  Provision  for  Expansion. — Such  rapid  progress  is  now  being 
made  in  all  lines  of  manufacture,  that  no  plant  would  be  eco- 
nomically planned  without  provision  for  expansion.  It  should  in 
fact  be  so  designed  that  extension  can  go  on  at  any  time  without 
serious  interference  with  operation — a  good  way  being  to  lay  out  a 
plant  much  larger  than  needed,  and  to  build  only  part  of  it  at  first. 
In  many  lines  of  business  it  is  quite  safe  to  anticipate  an  increase 
of  100  per  cent,  in  ten  years,  or  10  per  cent,  annually.  In  contrast 
to  systematic  provision  for  extension,  may  be  seen  many  old 
plants  which  have  been  enlarged  by  placing  new  buildings 
haphazard,  wherever  space  could  be  found,  so  that,  viewed  as  a 
whole,  the  ultimate  condition  shows  no  premeditation.  They 


FIG.  7. 

are,  in  fact,  nothing  more  than  a  cluster  of  scattered  buildings  in 
which  business  must  be  conducted  under  serious  disadvantage. 
To  extend  a  plant  by  crossing  streets  in  tunnels  or  over  bridges, 
is  not  convenient  and  can  usually  be  avoided  if  considered  in 
time.  Some  English  shops  prefer  sideway  expansion  by  the 
removal  of  a  side  wall,  and  the  addition  of  new -buildings  with 
longitudinal  roof  gutters  between  them.  Endway  extension, 
wings,  or  upper  stories,  are  other  methods  of  accomplishing  the 
same  result.  Preliminary  provision  must  also  be  made  for  extra 
land  and  for  the  extension  of  yards,  service  tracks  and  trolley 
lines.  Walls  which  must  ultimately  be  removed  should  at  first 
be  made  temporary  or  of  material  which  can  easily  be  taken  down, 
and  reinforced  concrete  should  be  avoided  unless  designed  with 
joints.  Plank  or  sheet  metal  may  be  good  enough  if  the  buildings 
are  not  difficult  to  heat. 

9.  Arrangement  of  Departments. — After  the  machinery  has 
been  arranged  and  the  floor  area  of  each  department  deter- 
mined, including  provision  for  receiving,  storing  and  shipping,  as 
well  as  for  extension  of  each,  the  various  departments  should 


28       ENGINEERING  OF  SHOPS  AND  FACTORIES 

then  be  assembled  into  buildings,  using  regular  types  as  far  as 
possible.  Those  departments  which  have  noise,  smoke,  dust, 
gas,  fumes,  odors,  or  fire,  must  usually  be  separated  from  the 
rest.  These  will  include  the  rooms  for  painting,  japanning, 
grinding,  polishing  and  rattling.  A  foundry  and  a  machine  shop 
cannot  well  be  placed  in  the  same  building,  for  the  dust  from  the 
first  would  be  a  serious  injury  to  machines,  and  the  engine  and 
boiler  rooms  of  power  plants  should  be  separated  by  a  brick  fire 


FIG.  8. — Plan  of  buildings  as  used  on  new  car  shops  of  the  Canadian  Northern 
Railroad  Company. 

wall.  Yet,  as  previously  stated,  buildings  of  regular  type  are 
preferable  to  special  ones,  for  rearrangements,  if  needed  are  more 
easily  made.  Union  and  non-union  men  must  sometimes  be 
housed  in  different  buildings.  Departments  and  buildings  should 
be  arranged  as  compactly  as  possible,  with  space  enough  around 
and  between  them,  and  yet  with  no  excess,  so  there  will  be  no 
useless  travel,  an  excellent  example  being  the  Allis-Chalmers 
plant  in  Milwaukee.  In  special  buildings  of  one  story,  shop  offices 
will  have  better  light  and  air  when  set  out  from  the  regular  shop 


ECONOMICS  OF  FACTORY  CONSTRUCTION       29 

rectangle.  Such  enclosures  as  tool  rooms,  offices,  lockers,  and 
toilets  may  sometimes  be  on  a  gallery,  though  access  by  stairs 
is  an  inconvenience.  Some  areas  may  not  need  enclosing,  and 
may  as  well  be  out  of  doors  with  a  saving  of  expense.  When 
time  will  permit,  it  may  be  an  advantage  to  make  drawings 
showing  several  proposed  arrangements  of  departments,  and  in 
the  final  composite,  to  include  the  best  features,  of  them  all. 
The  grouping  of  buildings  should  conform  to  the  course  in 
which  goods  travel  in  process  of  manufacture.  In  the  Allis- 
Chalmers  plant  at  Milwaukee,  for  the  manufacture  of  engines  and 


FIG.  9. — Plant  of  National  Portland  Cement  Co.,  Durham,  Ontario. 

machinery,  several  separate  but  parallel  machine  shops  are  con- 
nected at  one  end  to  an  erecting  shop,  while  at  the  other  end  but 
separated  from  the  machine  shops,  are  a  pattern  shop  and 
foundry,  the  axes  of  which  are  parallel  to  the  erecting  shop. 
When  additional  floor  space  is  needed,  the  erecting  and  pattern 
shops  and  the  foundry  can  be  extended  endways,  and  more 
machine  shops  placed  between  them. 

Another  method  of  grouping  buildings  which  is  very  effective,  is 
to  arrange  them  normal  to  and  right  and  left  of  a  central  axis, 
additions  to  the  buildings  when  needed,  being  made  at  their 
outer  ends  (Fig.  8\  Extensions  do  not  then  disturb  the  original 
departments  or  cause  any  rearrangement.  This  method  of 
grouping  is  used  on  the  new  car  shops  of  the  Canadian 
Northern  Railway  Company  at  Winnipeg,  and  is  said  to  be  ideal; 


30       ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  central  axis  in  this  case  being  an  elevated  craneway  covering 
the  tracks  which  enter  the  consecutive  buildings  (Fig.  110). 

10.  Preparatory  Design  of  Buildings. — When  departments 
have  been  grouped  and  arranged  with  reference  to  each  other, 
sketch  designs  may  be  made  of  the  buildings  showing  the  type 
and  materials  of  construction  (Fig.  9).  The  choice  of  building 
type  is  sometimes  affected  bytheir  contents  and  the  outside  fire 
risk,  though  in  most  cases  a  fireproof  building  is  preferable  to  one 
which  is  not  fireproof,  especially  when  their  cost  is  nearly  the 
same.  Fine  buildings,  when  well  located,  are  in  thejmselves  an 
advertisement,  and  they  tend  to  attract  and  hold  a  proficient 
grade  of  workmen.  The  buildings  should  facilitate  production 
by  their  good  light,  pure  air,  and  convenient  arrangement,  and  by 


FIG.  10. — Plant  of  the  Gulf  Bag  Co.,  New  Orleans,  La. 

their  equipment  for  lifting  and  transporting  materials.  No  part 
of  the  framing  should  ever  interfere  with  or  hinder  the  processes 
of  production. 

Some  expenditure  may  be  permissible  above  the  absolute 
minimum,  though  this  will  depend  on  circumstances.  It  is 
better  to  invest  less  money  in  the  plant  than  to  incur  a  debt  that 
will  make  dividends  impossible.  Moreover,  the  proposed  new 
industry  may  be  out  of  date,  and  the  buildings  used  for  other 
purposes  long  before  permanent  ones  are  worn  out.  This  con- 
dition was  well  illustrated  in  the  manufacture  of  bicycles,  for 
only  a  few  years  ago  many  plants  were  busily  engaged  in  making 
them.  As  the  demand  for  them  has  to  a  great  extent  ceased; 
these  shops  have  been  put  to  other  uses;  and  it  is  quite  possible 


ECONOMICS  OF  FACTORY  CONSTRUCTION       31 

that  some  shops  especially  built  for  the  manufacture  of  auto- 
mobiles may  likewise  be  put  to  other  uses  when  the  novelty  of 
these  conveyances  and  the  popular  desire  for  them  has  dimin- 
ished. The  general  rule  is  that  investments  are  permissible 
when  the  corresponding  saving  or  return  from  such  investments 
will  pay  interest  on  the  money,  together  with  maintenance,  cost 
and  depreciation,  with  something  left  over  for  profit.  This  is 
affected  by  the  rate  of  interest,  the  number  of  years  that  the 


FIG.  11. — Sketch  for  a  porposed  light  metal  working  shop. 

building  will  last,  and  its  ultimate  scrap  value  when  worn  out. 
In  the  design  of  buildings,  as  well  as  in  the  selection  of  equipment, 
the  final  result  is  usually  somewhere  between  the  two  extremes 
of  a  perfect  shop  and  a  practical  one. 

When  a  type  of  building  has  been  chosen  which  is  best  suited 
to  the  case,   outline  plans   and  elevations  with  one  or  more 

Note.— FIGS.  11  and  12  from  Article  by  D.  C.  N.  Collins,  Engr.  Magazine, 
Sept.,  1907. 


32       ENGINEERING  OF  SHOPS  AND  FACTORIES 


perspectives  should  be  made,  that  the  owner  may  see  clearly 
how  his  plant  will  appear  when  finished  (Figs.  10,  11,  12). 

11.  Approximate  Cost  Estimate. — After  departments  have 
been  arranged  and  grouped  in  buildings  to  the  best  advantage, 
an  approximate  estimate  should  be  made  of  the  whole  plant  as 
proposed.  Cost  units  should  be  large  enough  and  liberal. 
Buildings  may  be  figured  at  an  approximate  cost  per  square 
foot  of  floor  area,  or  per  cubic  foot  of  contents;  land  at  the 
assumed  price  per  acre;  machine  equipment  at  a  certain  unit 
price  per  square  foot  or  per  employee,  which  unit  will  vary  for 


FIG.   12. — Preliminary  sketch  for  an  engine  and  boiler  works. 

different  kinds  of  shops.  The  equipment  in  machine  shops  for 
the  manufacture  of  medium  or  heavy  machine  tools,  will  cost 
about  $600  per  employee,  or  about  $8  per  square  foot  of  shop 
floor. 

Before  submitting  outline  plans  and  estimates  to  the  owner, 
the  engineer  should  figure  out  a  number  of  alternates  by  which 


ECONOMICS  OF  FACTORY  CONSTRUCTION       33 

the  cost  could  be  reduced,  for  an  owner  often  thinks  at  first 
that  he  needs  a  larger  plant  than  he  is  finally  willing  to  accept 
when  the  cost  is  considered.  Every  item  of  the  estimate  should 
be  carefully  examined  to  see  if  it  is  warranted,  and  the  engineer 
should  be  prepared  to  show  where  possible  changes  can  be  made, 
and  how  such  will  affect  the  cost. 

Plans  and  estimates  should  then  be  presented  to  the  owner, 
that  he  may  see  if  the  prospective  business  and  profits  are  enough 
to  justify  the  investment.  If  the  expense  is  too  large,  which  is 
often  the  case  at  first,  the  scope  must  be  reduced.  When  both 
owner  and  engineer  are  satisfied  that  the  proposed  layout  and 
arrangement  are  satisfactory  both  as  to  efficiency  and  cost,  it  is 
then  time  to  proceed  with  the  making  of  detail  plans  and  specifi- 
cations, and  with  actual  construction.  The  preparatory  work 
which  is  sometimes  done  by  a  mechanical  or  plant  engineer  in 
consultation  with  the  owner,  is  then  completed. 


CHAPTER  IV 

PRELIMINARY  DESIGN  AND  REPORT   FOR  A  STRUCTURAL 

PLANT 

In  order  to  more  fully  illustrate  the  subject,  an  example  is 
given  of  a  preliminary  design  and  report  for  a  proposed  plant, 
made  by  the  writer  about  twelve  years  ago.  A  small  plant  is 
chosen  in  preference  to  some  larger  ones,  as  it  illustrates  the 
subject  quite  as  well,  with  less  complexity  of  detail.  The  plant 
was  an  addition  to  a  rolling  mill  which  was  then  equipped  with 
machine  and  forge  shops,  and  served  by  both  rail  and  water 
shipping.  The  report  is  reproduced  in  full  as  originally  made. 

Location. — The  most  desirable  location  for  the  bridge  plant  is 
somewhere  in  the  vicinity  of  the  steel  mill  from  which  the 
structural  shapes  will  be  received. 

As  a  large  part  of  the  output  from  the  bridge  shop  would  be 
shipped  by  water,  it  is  desirable  to  place  it  near  the  river.  A 
site  just  west  of  the  dock  would  probably  be  suitable. 

It  has  the  disadvantage  of  being  low  and  wet,  and  would 
require  considerable  grading  and  filling,  probably  not  less  than 
2  ft.  Some  of  the  material  for  filling  would  be  taken  from  the 
building  and  machine  foundations,  but  the  greater  part  of  it 
would  need  to  be  hauled  in  on  cars. 

The  triangular  piece  of  ground,  bounded  by  three  lines  of  rail 
track  at  the  east  end  of  the  steel  plant  would  be  desirable. 
This  site  is  drained  by  the  main  sewer. 

Size  of  Lot. — To  carry  out  the  scheme  outlined  in  this  report, 
the  size  of  lot  required  is  not  less  than  400  by  1000  ft. 

One  of  the  chief  requirements  of  a  modern  bridge  plant  is 
ample  yard  room. 

At  one  end  of  the  yard,  stock  should  be  well  spread  out  on 
skids,  that  it  may  be  easily  reached  with  little  handling.  This 
end  of  the  yard  should  be  intersected  with  numerous  service 
tracks. 

At  the  other  end  of  the  yard,  where  the  loading  is  done,  there 
should  be  ample  room  for  the  storage  of  finished  products,  and 

34 


DESIGN  FOR  A  STRUCTURAL  PLANT  35 

also  for  loading  them  on  cars.  There  should  be  space  for  loading 
several  cars  at  one  time,  and  additional  space  for  shop  extension, 
or  the  erection  of  other  small  buildings  as  may  be  required. 

Grading  of  Site. — It  is  desirable  to  slope  the  entire  site  on  a 
down  grade  of  about  1  per  cent,  in  the  direction  that  the  material 
goes  in  passing  through  the  works.  The  cost  of  this  will  depend 
on  the  site  selected. 

Arrangement  of  Yard. — The  templet  shop  and  the  stock  yard 
are  located  near  one  end  of  the  main  shop.  From  these,  the 
stock  and  templets  will  be  taken  to  the  laying-out  department. 

It  will  then  pass  on  to  the  punches  and  shears,  thence  to  the 
assemblers,  reamers  and  riveters,  and  last  to  the  milling  and  bor- 
ing machines.  It  is  then  passed  out  at  the  other  end  of  the  shop, 
painted,  and  loaded  on  cars. 

The  broad  gauge  shipping  track  is  shown  passing  between  the 
main  shop  on  one  side  and  the  templet  and  forge  shops  on  the 
other. 

The  main  building  will  have  two  lines  of  service  tracks  passing 
through  its  entire  length,  and  the  forge  shop  will  have  a  single 
line  of  track. 

The  stock  yard  will  have  several  parallel  lines  of  service  tracks 
which  are  connected  by  a  transfer-way.  A  service  car  on  any 
track  can  then  be  run  on  the  truck  in  the  transfer-way,  and  run 
off  again  on  any  desired  track. 

Cost  of  the  service  tracks  need  not  exceed  $2500. 

Economic  Production. — In  order  to  produce  economically,  and 
compete  successfully  for  work,  it  is  necessary  that  the  equipment 
should  be  the  best  that  can  be  secured. 

In  estimating  on  the  plant,  only  such  an  equipment  has  been 
included  as  is  necessary,  but  everything  is  of  the  best. 

Co-operation  with  Present  Machine  Shop  and  Foundry. — These 
shops  are  already  well  equipped,  and  after  the  new  construction 
is  finished,  will  doubtless  be  able  to  make  some  parts  required  by 
the  structural  plant. 

Such  parts  as  bridge  pins,  turned  bolts,  machine  screws, 
finished  castings,  etc.,  can  be  made  in  the  machine  shop. 

The  foundry  can  produce  all  the  necessary  iron  castings,  and 
equipment  for  making  steel  castings  can  be  added.  These  will 
frequently  be  required  in  first-class  work. 

At  present  there  is  a  corner  of  the  machine  shop  used  for 
boiler  work. 


36       ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  tools  in  this  corner  can  be  transferred  to  the  structural 
shop,  and  all  such  work  done  there  in  the  future. 

This  will  leave  more  room  in  the  machine  shop,  which  appears 
crowded  at  present. 

Scope  of  Plant. — This  estimate  is  for  a  shop  equipped  to  manu- 
facture all  kinds  of  bridge -'and  structural  work,  including  pin- 
connected  and  riveted  bridges,  plate  girders,  both  light  and 
heavy,  steel  frames  for  buildings,  beams,  trusses,  columns,  tanks, 
ore  boxes,  etc.,  etc.  Only  three  principal  buildings  are  outlined 
at  present,  viz.:  the  templet  shop,  forge  shop  and  riveting  shop. 

The  templet  shop  is  to  be  a  two-story  building.  The  upper 
floor  is  to  be  finished  smooth,  and  large  enough  to  lay  out  templets 
for  large  riveted  sections,  such  as  roof  trusses,  etc. 

The  first  story  will  be  used  at  one  end  for  the  storage  and 
drying  of  lumber,  and  at  the  other  end  for  a  drafting  office. 

The  forge  shop  is  shown  close  enough  to  the  main  shop  so  that 
loads  of  angles  or  beams  that  must  be  heated  and  bent,  may  be 
easily  transferred  from  one  shop  to  the  other  and  back  again. 

It  would  not  be  economical  to  send  such  heavy  material  over 
to  the  present  blacksmith  shop,  a  distance  of  nearly  one  mile,  and 
back  again  to  the  structural  shop  for  riveting  and  punching. 

Loop  rods,  clevises,  rivets,  and  miscellaneous  forging  will  be 
done  here. 

There  will  be  an  up-setting  machine,  an  annealing  furnace, 
power  hammers,  etc. 

The  roof  trusses  will  be  arranged  with  trolleys  and  hoists  for 
lifting  material. 

The  riveting  shop  will  have  traveling  carriages,  trolleys,  and 
hoists  heavy  enough  to  handle  the  heaviest  girders,  and  other 
lighter  ones  for  lighter  and  smaller  work. 

The  buildings  will  all  be  well  lighted. 

The  forge  shop  will  have  a  timber  frame. 

For  the  other  two  buildings,  estimates  are  made  for  making 
the  walls  either  of  masonry,  or  corrugated  iron  on  plank. 

To  start  with,  it  is  the  intention  to  have  only  such  buildings 
and  tools  as  are  necessary  to  turn  out  work  economically. 

Other  small  buildings  may  be  added  in  the  future. 

Future  Extension  of  Plant.— The  design  should  be  made  so  that 
the  end  can  be  removed  and  the  buildings  made  longer. 

Other  small  buildings  will  be  required  as  business  increases. 
The  following  may  be  needed : 


DESIGN  FOR  A  STRUCTURAL  PLANT  37 

Paint  shop, 

Storage  house  for  erection  tools  and  rigging, 

Separate  office  building, 

Plate  bending  shed,  etc., 

but  none  of  these  are  included  in  the  present  estimate. 

Method  of  Constructing  Buildings. — The  forge  shop  may  be 
put  up  first  and  used  temporarily  as  a  structural  shop.  This  is 
designed  with  a  wood  frame  that  can  be  built  on  the  ground  by 
carpenters. 

Only  such  tools  need  be  used  as  are  necessary  for  manufactur- 
ing the  frames  for  the  other  two  buildings.  These  machines  may 
be  placed  on  temporary  timber  foundations. 

Templets  for  these  two  buildings  may  be  made  in  the  present 
pattern  shop,  and  drawings  in  the  attached  office. 

Then  when  the  permanent  buildings  are  constructed,  the  tools 
may  be  removed  from  the  forge  shop  to  the  main  riveting  shop, 
and  set  up  on  concrete  foundations. 

Under  these  conditions,  the  cost  of  manufacture  will  of  course 
be  excessive,  but  it  will  be  quite  as  satisfactory  as  waiting  for 
some  other  shop  to  manufacture  the  frame. 

FORGE  SHOP 

Size:  40  ft.  by  100  ft.     20  ft.  under  trusses. 
Wood  frame.     Covering,  corrugated  iron  on  plank. 
Trusses  8  ft.  apart. 
Trolleys  on  tie  beams. 

10-ft.  continuous  sash  all  around  under  eaves. 
8-ft.  monitor  with  swing  sash. 

ESTIMATE  OF  COST 

Cost  of  building  complete  (including  foundations) .  $3500 

Machinery: 

1  up-setting  machine $  800 

1  rivet  and  bolt  former 1200 

1  annealing  furnace 300 

4  forges  (from  present  blacksmith  shop) 

4  anvils  (from  present  blacksmith  shop) 

1  steam  hammer 800 

1  steam  hammer 1500 

6  hoists  at  $50 300 

100  ft.  track 60 

4  service  cars. .  160         5120 


Total  cost .  .  .  $8620 


38       ENGINEERING  OF  SHOPS  AND  FACTORIES 

TEMPLET  SHOP  AND  OFFICE 

Size:  60  ft.  by  150  ft.  Two  stories.  Steel  frame.  Masonry  walls. 
Cost  of  building,  complete,  including  floor,  foundations,  light- 
ing, heating,  etc $14,300 

If  the  walls  are  made  of  plank,  covered  with  corrugated 

iron,  the  cost  will  be  $1800  less. 

Machinery:  ,„ 

1  wood  planer : $200 

6  drills 300 

1  saw 200 

1  band  saw 400 

1  motor 200 

Belts,  pulleys,  etc 200 

6  sets  small  tools 200  1,700 


Total  cost $16,000 

BRIDGE  SHOP 

Size:  80  ft.  by  400  ft.     22  ft.  high  under  trusses.     Steel  frame. 
Masonry  walls.     Roof:  corrugated  iron  -on  plank. 

Cost  of  building — including  floor  and  foundation .  .  $28,300 

Equipment: 

Cranes  and  hoists $17,500 

Heating 2,000 

Electric  lighting 800 

Machinery  foundations 1,200 

Skids  and  rails 1,300 

Service  tracks 800 

20  cars '          800  24,400 


Total  cost $52,700 

MACHINE  TOOLS  FOR  PROPOSED  BRIDGE  SHOP 

1  plate  shear  for  60  in.  Xl  in.  metal,  motor  driven $  4,500 

1  angle  shear  for  8  in.  X  8  in.  X 1  in 3,500 

1  angle  shear  for  5  in.  X  5  in.  X  3/4  in 2,500 

1  bar  shear  for  12  in. Xl  1/4  in. 2,000 

1  punch  30  in.  throat  for  11/4  in.  holes  in  1  in 1,600 

1  punch  20  in.  throat  for  1  1/4  in.  holes  in  1  in 1,500 

2  punches  10  in.  throat  for  angle  6  in.  X  6  in.  X 1  in 2,200 

1  plate  edge  planer 4,500 

1  boring  machine  for  pin-holes 1,500 

1  beam  saw  for  24  in.  beams 1,300 

1  beam  saw  for  15  in.  beams 600 

1  beam  coping  and  notching  machine 1,800 

Milling  machine,  54  in.  head 3,100 

Bender  and  straightener  for  beams  and  angles 2,200 


DESIGN  FOR  A  STRUCTURAL  PLANT  39 

1  air  compressor 2,500 

2  riveters,  25  in.  reach  (compressed  air) 800 

1  riveter,  36  in.  reach  (compressed  air) 500 

1  riveter,  54  in.  reach  (compressed  air) 500 

10  hoists 500 

12  drills  and  reamers 1,000 

Piping  for  drills  and  reamers 500 

Chippers  and  caulkers 500 

4  rivet  furnaces 200 

2  emery  wheels  |  _ 
2  grind  stones .  J 

1  bar  shear 500 

1  threading  machine  for  rods ,  400 

1  angle  heating  furnace 100 

4  electric  motors 800 

Total  cost $41,750 

Loading  Facilities. — To  load  heavy  work  economically,  an 
outdoor  traveling  crane  is  necessary. 

For  the  present,  however,  loading  may  be  done  by  two  derricks 
capable  of  lifting  about  20  tons  each.  They  may  be  operated 
by  two  electric  hoisting  engines. 

Cost  of  two  derricks  at  $400 $    800 

Cost  of  two  hoisting  engines  at  $600 1,200 

$2,000 

Erecting  Tools  and  Machinery. — The  number  of  erecting  tools 
and  amount  of  material  required,  depends  on  the  nature  of  the 
structure  to  be  erected,  and  the  number  of  contracts  on  hand  at 
any  one  time. 

In  erecting  the  frame  of  the  templet  and  bridge  shops,  the 
parts  may  be  hoisted  with  a  gin  pole. 

The  cost  of  the  necessary  rigging  including  rope,  pulleys,  hoists, 
guys,  timber,  gin  pole  and  hoisting  engine,  need  not  exceed 
$1500. 

Power. — In  the  bridge  shop,  all  of  the  large  machines  will  be 
driven  by  direct  connected  electric  motors,  and  the  small  ones 
by  compressed  air. 

A  few  small  ones  such  as  threading  machines,  grinders,  etc., 
will  be  belt  driven.  These  may  be  grouped  and  the  overhead 
shafting  turned  by  a  separate  electric  motor. 

The  templet  shop  machinery  may  be  belt  driven,  and  power 
furnished  by  a  separate  electric  motor. 


40       ENGINEERING  OF  SHOPS  AND  .FACTORIES 

COST  OF  COMPLETE  BRIDGE  PLANT 

Summary : 

Grading $     3,000 

Service  tracks 2,500 

Forge  shop,  building 3,500 

Forge  shop,  tools 5,120 

Templet  shop  and  office. , 14,300 

Machinery .......:" 1,700 

Bridge  shop,  building  and  equipment, 52,700 

Bridge  shop,  tools 41,750 

Loading  derricks  and  engines 2.000 

Erecting. 1,'500 


Total  cost $128,070 

MACHINE   TOOLS  FOR  TEMPORARY   SHOP— 40  FT.    BY   100  FT. 

1  plate  shear,  for  36  in.  X 1  in $  2,500 

1  angle  shear,  for  6  in.  X  6  in.  X  £  in 2,500 

1  bar  shear,  for  12  in.  X 1  in 2,000 

1  punch,  30  in.  throat 1,600 

1  punch,  10  in.  throat 1,100 

1  beam  saw  for  24  in.  beams 1,300 

Coping  and  notching  machine 1,800 

Bender  and  straightener . .    2,200 

Air  compressor 2,500 

2  riveters  (compressed  air) 800 

10  hoists  (compressed  air) 500 

12  drills  and  reamers  (compressed  air) 1,000 

Piping  for  drills  and  reamers 500 

Chippers  and  caulkers 500 

2  rivet  furnaces 100 

1  threading  machine 400 

2  motors .  .  400 


Total $21,700 

COST  OF  TEMPORARY  PLANT 

One  building  40  ft.   by   100  ft.   and  machinery  necessary  for  making 
building  frames. 

Grading $      500 

Service  tracks 400 

Building 3,500 

Tools 21,700 

Loading  derricks  and  engines 2,000 

Erecting  tools 1,500 

Total  cost .  .                                                      $29,600 


DESIGN  FOR  A  STRUCTURAL  PLANT  41 

PROFIT  ON  INVESTMENT 

Count  then  on  an  output  of  10,000  tons  per  year,  which 
is  a  low  estimate.  From  personal  knowledge  competitors  are 
producing  20,000  tons  per  year. 

Value  of  10,000  tons  at  $70  per  ton  is $700,000 

Profit  at  10  per  cent 70,000 

Proposed  investment $130,000 

Interest  on  $130,000  at  7  per  cent 9,100 

Depreciation  on  stock  at  3  per  cent 3,900 


$  13,000 
Net  profit:  $70,000,  less  $13,000,  equals  $57,000 

This  is  44  per  cent,  clear  yearly  profit  on  the  money  invested. 


CHAPTER  V 

j# 

GENERAL  DESIGN 

Having  completed  investigations  of  the  Economics  of  Factory 
Construction,  and  decided  all  matters  relating  to  the  effect  of 
buildings  upon  output  and  efficiency,  detail  designs,  drawings, 
and  specifications  must  be  prepared.  These  will  be  based  upon 
the  outline  sketches  or  perspectives  and  cost  estimates  previously 
made. 

Construction  bids  on  proposed  new  buildings  are  usually 
lowest  when  drawings  are- very  plain,  with  little  or  no  chance  for 
misunderstanding.  The  reason  for  this  is  evident,  as  all  con- 
tractors then  have  exactly  the  same  data  upon  which  to  base 
their  bids,  and  tenders  are  likely  to  be  more  uniform.  On  the 
other  Hand,  if  the  plans  are  indefinite,  contractors  will  not 
feel  safe  in  bidding  unless  an  item  is  added  to  cover  uncer- 
tainties. Clear  and  accurate  working  drawings  also  pay  for 
themselves  many  times  over  in  the  mistakes  which  are  thereby 
avoided. 

While  standard  house  plans  in  book  form  are  abundant,  there 
seems  to  be  little  or  nothing  of  the  kind  yet  available  for  shops 
and  factories,  new  ones  in  nearly  all  cases  being  built  to  order. 
This  need  for  special  planning  makes  plenty  of  work  for  Mill  and 
Industrial  Engineers.  In  addition  to  the  detail  plans  for 
construction,  drawings  must  also  be  made  for  the  interior  equip- 
ment, including  heating,  ventilating,  lighting,  plumbing,  electric 
wiring,  power  generation  and  transmission,  line  shafting,  fire 
protection,  handling  appliances,  yards  and  tracks,  and  for  all 
other  features  of  a  special  nature.  The  building  must  serve  as  a 
shelter  for  its  occupants  and  equipment,  should  give  support  for 
shafting  and  machinery  when  needed,  and  form  support  for 
crane  and  other  handling  appliances.  It  should  also  facilitate 
as  far  as  possible  the  economic  management  of  labor. 

Before  starting  detail  drawings,  the  structural  engineer  if  he 
is  not  already  supplied,  should  have  data  or  suggestions  from 
the  owner  on  matters  pertaining  to  construction,  so  that  the 

42 


GENERAL  DESIGN  43 

owner's  preferences  in  these  matters  may  be  observed  and  the 
plans  and  specifications  suited  to  conditions.     He  should  also 
have  complete  data  on  the  following  subjects: 
Climate,  possibility  of  earthquakes  or  cyclones,  prevailing  storms, 

extremes  of  heat   and   cold,   maximum  precipitation  and 

snow  fall,  depth  of  winter  frost,  etc. 
Survey  of  lot,  showing  storm  and  roof  sewers,  sanitary  sewers, 

grade  and  lot  lines,  water  and  gas  pipes,  etc. 
Nature  and  bearing  power  of  soils. 

Local  laws  relating  to  building  construction,  smoke,  etc. 
Regulation  of  fire  insurance  companies. 
Proposed  water  supply  for  shop  service,   sanitation,   fire  and 

sprinkler  pipes,  condensers,  etc. 
Machinery  layout  for  each  department. 

Assumed  floor  loads — weights  of  largest  pieces,  crane  loads,  etc. 
Foundations  for  buildings,  machines,  yard  cranes,  etc.,  with  note 

of   special   provision   for   underground   pipes,    tunnels,    or 

drains,  which  may  interfere  with  foundations. 
Height  of  stories,  or  overhead  space  for  largest  machines  and 

materials. 
Power  and  transmission,  whether  by  belt,  rope,  shafting,  electric 

wires,  with  provision  for  steam  and  air  pipes  where  needed. 
Methods  of  heating. 
Ventilating  methods. 
Lighting   of  shops,   yards,    and   entrances,   particularly  where 

affected  by  adjoining  high  buildings. 
Plumbing  and  sanitation  and  the  effect  of  health  regulations 

thereon.     Installation  of  pipes  for  air,  water  and  sprinkler 

systems. 

Fire  protection  system. 

Conveying  and  hoisting  appliances  for  materials. 
Arrangement  of  tracks,  switches,  scales,  etc. 
Width  of  building,  position  of  columns,  kind  of  material,  floors, 

walls,  partitions,  doors,  windows,  roof  framing,  roofing,  and 

other  features  of  construction. 

Many  of  these  subjects  will  be  discussed  in  the  following  pages, 
and  each  must  receive  the  attention  that  it  merits. 

Photographs  should  be  freely  made  about  the  new  site  and 
then  numbered,  the  direction  in  which  each  one  was  taken  being 
indicated  by  an  arrow  with  its  corresponding  number  on  a  print 
of  the  lot  plan.  These  photographs  will  be  useful  for  reference 


44       ENGINEERING  OF  SHOPS  AND  FACTORIES 

in  the  engineer's  office  and  are  always  valuable  records  which 
cannot  be  disproven. 

Esthetic  Treatment. — Artistic  treatment  of  modern  plants  is 
often  a  part  of  a  definite  policy  of  their  owners.  It  may  be 
carried  out  for  the  purpose  of  advertising,  or  to  attract  and  hold 
a  good  class  of  employees,  welfare  features  often  being  introduced 
for  the  same  reason.  Buildings  may*  indeed  often  be  made 
attractive  in  appearance  (Fig.  13)  at  little  or  no  increased  cost 
over  those  which  are  severely  plain.  The  tendency  in  recent 
years  is  to  beautify  not  only  manufacturing  plants,  but  all  other 
utilitarian  structures  and  engineering  works  such  as  dams,  power 
plants,  bridges,  etc.  Water  towers  when  enclosed  with  walls, 


FIG.  13. — Office  and  works  of  Pawling  &  Harnischfeger  Co.,  Milwaukee,  Wis. 

have  a  better  appearance  than  those  with  gaunt  and  open  fram- 
ing. Colored  tiles  may  be  used  on  roofs,  and  walls  may  be 
relieved  with  cornices,  pilasters,  and  base  of  different  material 
or  colored  paneling  (Fig.  14).  Interiors  of  buildings  may  be 
painted  white  or  some  light  hue,  and  may  be-  relieved  with  a 
simple  stencil  course  on  the  walls  near  the  ceiling,  or  with 
occasional  decorative  panels. 

Wind  Pressure. — Wind  pressure  on  relatively  small  areas 
varies  in  amount  with  the  height  above  the  ground.  This  was 
proven  by  experiments  made  in  England  by  Stephenson,  on 
surfaces  at  heights  of  5,  10,  15,  25  and  50  ft.  above  ground,  his 
observations  covering  air  currents  of  varying  velocities  with 


GENERAL  DESIGN 


45 


pressures  of  4  to  43  Ib,  per  square  foot, 
of  these  experiments  are  as  follows: 


The  average  results 


FIG.  14. — Details  of  market  building. 

STEPHENSON'S  EXPERIMENTS  FOR  WIND  PRESSURE 
Height  above  ground  Wind  pressure  per  square 

foot  in  pounds 


in  feet 
50 
25 
15 
10 
5 


29.1 
25.9 
22.8 
21.2 
13.8 


These  results  show  relative  proportions  only,  on  compara- 
tively small  exposed  areas.  As  buildings  tend,  more  or  less, 
to  shelter  each  other,  especially  in  districts  where  they  are  well 
surrounded,  it  is  usually  sufficient  at  a  height  of  80  ft.  or  more 
above  ground,  to  provide  for  a  wind  pressure  of  40  Ib.  per  square 
foot  and  for  less  height  to  reduce  this  pressure  according  to  the 
formula  P=4\/ff  +  5 


46       ENGINEERING  OF  SHOPS  AND  FACTORIES 


80 


70 


where  P  is  the  wind  pressure  in  pounds  per  square  foot,  and  H 
the  height  in  feet  to  the  area  in  question.  This  gives  results  con- 
forming closely  with  Stephenson's  experiments,  the  results  being 
shown  on  the  following  diagram. 

As  a  wind  pressure  of  30  Ib.  per  square  foot  corresponds  with  a 
velocity  of  70  to  80  miles  per  hour,  and  can  occur  only  during 
violent  storms  or  hurricanes  in 'exposed*  places,  it  is  rare,  indeed, 
when  a  greater  pressure  need  be  assumed.  The  tendency  in  urban 
districts,  for  buildings  to  shelter  each  other,  is  so  effective  that  it  is 
frequently  quite  safe  to  entirely  disregard  wind  pressures  up  to  a 
height  of  20  to  30  ft.  above  ground.  There  is  a  tendency  on  large 
wall  areas  toward  equalization  of  pressure  at  varying  heights, 

owing  to  the  elasticity  of  the  air, 
the  condition  being  different  to 
that  in  Stephenson's  experiments, 
which  were  on  small  areas. 

Wind  pressure  on  the  interior 
of  buildings  may  be  serious,  es- 
pecially where  the  sides  are  partly 
open,  or  broken  with  many  doors 
or  windows  through  which  air  cur- 
rents may  enter.  Need  of  protec- 
tion against  inside  upward  pres- 
sure has  long  been  known,  for  in 
some  exposed  districts  in  Europe, 
it  has  been  the  custom  for  the 
peasants  to  load  their  roofs  with 
rocks.  The  ends  of  high  single- 
story  buildings,  such  as  erection 
shops  with  traveling  cranes,  are 
often  harder  to  brace  than  are  the 
sides,  for  they  lack  substantial 
bracing  at  the  lower  chord  level 
and  at  intermediate  heights. 
When  the  sides  are  open  enough  to  admit  free  air  currents,  wind 
pressure  on  the  two  sides  will  be  nearly  equal,  and  the  sum  of 
these  sides  will  be  the  area  under  pressure.  Wind  conditions 
will  evidently  vary  in  different  buildings,  and  each  one  should  be 
proportioned  according  to  its  needs. 

Pressure  normal  to  the  roof  surface  for  angles  up  to  75  degrees 
from  the  horizontal,  corresponding  with  wind  pressures  of  40  Ib. 


a  50 


o 
U  40 


20 


7 


0  10  20  30  40 

Maximum  Pressure  in  Lbs.  per  Sq.  Ft. 

FIG.  15. 


GENERAL  DESIGN 


47 


per  square  foot,  on  a  vertical  surface  may  be  obtained  from  the 
following  formula: 

P  =40  sin  (A  + 15  degrees) 

where  A  is  the  angle  which  the  roof  plane  makes  with  the  horizon- 
tal. The  results  are  conveniently  shown  by  the  following 
diagram,  which,  if  made  on  tracing  cloth,  may  be  laid  over  roof 
drawings  of  any  slope  and  the  corresponding  normal  wind  pres- 
sure read  off  directly. 


p-  40  sin  (0  +  15°) 


4Q  30 


20  10  10 

Wind  Pressure  in  Lbs.  per  Sq.  In. 

FIG.  16. 


30  40 


Floor  Loads. — Live  loads  on  floors  vary  greatly  according  to 
the  industry,  the  largest  ones  frequently  being  in  metal  working 
shops.  The  floors  of  cotton  mills  can  generally  be  light,  for  the 
total  weight  of  machinery,  men  and  materials  will  seldom  exceed 
30  Ib.  per  square  foot.  Stories  8  to  9  ft.  in  height  used  for  the 
storage  of  cotton  bales,  should  be  proportioned  for  an  imposed 
load  of  100  to  150  Ib.  per  square  foot,  while  higher  ones  for  general 
storage  and  packing,  might  be  subject  to  200  Ib.  Rooms  for 
pattern  storage  rarely  carry  more  than  150  Ib.  on  the  square  foot. 
Buildings  for  light  machinery  frequently  have  provision  for 
loads  of  250  to  300  Ib. 

Unit  Stresses. — A  factor  of  four  is  sufficient  for  dead  and  live- 
load  stresses,  but  for  greater  combinations  such  as  dead,  live,  and 
crane  loads  all  acting  together,  a  factor  of  safety  of  three  is 
enough.  The  temporary  buildings  for  the  Columbian  Exposition  at 
Chicago  in  1893,  were  proportioned  for  tensile  stresses  of  20,000 
to  25,000  Ib.  per  square  inch  of  section  on  steel.  Comparatively 


48       ENGINEERING  OF  SHOPS  AND  FACTORIES 


high  unit  stresses  are  usually  permissible  on  buildings  excepting 
perhaps  in  columns,  for  it  is  well  known  that  such  structures  rarely 
fail  by  the  collapse  of  their  principal  parts,  but  rather  rack  to 
pieces  from  the  vibration  of  cranes  and  heavy  machinery. 


ROOF    TRUSSES. 
Stresses,  Bevels  and  Lengths, 
iib. 


To  find  stresses  in 
any  truss,  multiply 
stresses  given  by 
the  panel  load. 


Hlb. 


To  find  stresses  in 
any  truss,  multiply 
stresses  given  by 
the  panel  load. 


lib. 


1  Ib. 


E 
P 

To  find  stresses  in 
any  truss,  multiply 
stresses  given  by 
the  panel  load. 


FIG.  17. 

Stress  Analysis  in  Building  Frames. — The  cases  to  be  considered 
in  determining  the    stress  in  building   frames   are   as  follows: 

1.  Stress  in  roof  trusses  and  columns  from  permanent  dead 
load. 

2.  Stress  from  wind  acting  normal  to  roof  surface,  with  trusses 
supported  on  side  walls. 


GENERAL  DESIGN 


49 


3.  Stresses  in  trusses,  columns  and  knee  braces,  from  wind  on 
side  of  building  and  roof,  either  horizontal  or  normal  to  surface, 
(a)  with  columns  hinged  as  base,  (b)  with  columns  fixed  at  base. 

Partial  loading  can  never  cause  maximum  stress  in  the  parts  of  a 
Fink  truss,  as  it  may  in  some  other  truss  forms. 

Calculation  of  truss  stresses  is  greatly  simplified  by  the  use  of 
coefficients  giving  the  stress  in  each  piece  from  panel  load  of 
unity,  some  of  these  coefficients  being  given  in  the  following 
diagrams. 

Knee  Braces. — Judging  from  the  elaborate  analysis  given  in 
some  books  of  the  stresses  in  building  frames  with  knee  braces, 


FIG.  18. 

a  person  might  almost  believe  that  this  comparatively  simple 
feature  should  receive  quite  a  large  part  of  an  engineer's  attention 
when  planning  such  structures.  On  the  contrary,  the  analysis 
of  such  stress  is  very  simple,  though  it  is  affected  to  some  extent 
by  local  conditions,  such  as  the  detail  of  column  base,  and  amount 
of  anchorage;  nature  of  walls,  whether  closed  or  partly  open,  etc. 
In  many,  if  not  in  most  cases,  the  experienced  designer  can  see 
from  inspection  that  computation  of  stresses  from  knee  braces 
is  unnecessary,  as  they  are  insignificant.  But  when  buildings 


50       ENGINEERING  OF  SHOPS  AND  FACTORIES 


are  high  and  exposed  to  strong  wind,  investigation  of  knee  brace 
stress  may  be  needed.  It  is,  however,  important  that  knee 
braces  have  rigid  framing  at  their  extremities  (Fig.  18) ,  and  they 
should  connect  to  a  truss  panel  where  the  members  are  heavy 
enough  to  resist  compression.  At  the  other  end  of  the  brace, 
the  column  must  be  firm  enough  to  resist  bending,  web  lattice 
frequently  being  too  light  for  rigidit-jr.  The  knee  brace  problem 
is  quite  similar  to  one  of  the  simplest  in  bridge  analysis,  viz., 
the  proportioning  of  portals.  Columns  may  be  considered  fixed 
at  the  base  when  they  are  firmly  anchored,  or  when  they  have 
snough  load  on  them  to  hold  them  squarely  down.  A  large  one- 
story  steel-frame  metal  working  shop  which  was  inspected  by  the 
writer  after  its  collapse  during  erection,  but  after  columns  had 
been"  anchored,  illustrates  the  case.  The  columns  remained 
with  their  bases  fixed  to  the  foundations  and  bent  at  about  one- 
third  of  their  height,  the  whole  frame  falling  in  one  direction. 


If 


FIG.  19. 

Pin  ended  action  is  seldom  found  in  building  columns.  Wind 
pressures  on  the  bents  may  usually  be  considered  as  transferred 
to  the  foundation  in  equal  amounts  on  the  two  sides,  for  if  the 
leaward  braces  and  columns  are  not  stressed  at  first,  deflection 
of  the  windward  side  will  bring  the  other  into  action. 

Columns  should  be  proportioned  not  only  for  their  direct 
load,  but  also  for  the  bending  stress  and  additional  load  on  them 
from  the  overturning  effect  of  wind  on  the  building  as  a  whole, 
causing  greater  load  on  the  windward  ones. 

Additional  Notes. — In  conclusion,  the  design  should  be  care- 
fully studied  out,  preferably  on  small  sheets  of  paper,  8j  by 
11  in.,  and  drawings  made,  giving  sizes  and  general  details. 
The  upper  flange  of  crane  girders  may  be  stiffened  laterally  by 


GENERAL  DESIGN  51 

placing  another  beam  or  channel  with  its  web  in  a  horizontal 
position  above  the  principal  one,  the  upper  one  being  riveted 
through  the  web  to  the  flange  of  the  one  beneath  it  (Fig.  19). 

The  design  should  also  be  checked,  and  every  part  reconsidered 
before  construction.  Any  parts  which  are  found  to  be  unneces- 
sary may  then  be  omitted,  or  additional  ones  may  be  introduced 
where  needed.  The  dead  weight  should  be  refigured  to  see  that 
it  does  not  exceed  that  which  was  assumed.  One  or  more  show 
plans  or  general  drawings  should  be  made,  giving  all  the  framing 
sizes  and  general  dimensions,  these  plans  serving  as  a  guide  for 
the  draftsmen  when  making  the  details. 

Specifications. — Unless  a  building  specification  is  clear  and 
definite,  misunderstanding  will -surely  arise,  with  correspondingly 
higher  tenders.  Successful  contractors  are  not  willing  to  take 
reckless  chances,  and  they  usually  add  enough  to  their  bids  to 
cover  any  points  which  are  indefinite.  Then,  if  the  contract  is 
secured,  and  construction  should  be  carried  out  in  a  cheaper  way, 
their  profit  would  be  increased.  For  the  sake  of  clearness,  the 
writing  of  specifications  should  be  deferred  until  all  details  of 
construction  are  well  in  mind.  A  good  way  is  to  carefully 
examine  all  drawings,  whether  complete  or  under  way,  and  to 
make  note  of  details  of  every  kind,  examining  each  sheet  thor- 
oughly in  all  particulars  before  taking  up  another  one.  Each 
note  should  be  made  on  a  separate  card  of  uniform  size  and  these 
may  afterward  be  arranged  under  different  headings,  those 
relating  to  masonry,  carpentry,  painting,  etc.,  each  being  kept 
by  themselves.  The  cards  for  each  heading  may  then  be  classi- 
fied in  proper  order.  In  this  way  a  logical  arrangement  is  easily 
obtained.  Before  writing  the  specifications  of  any  particular 
subject,  such  as  carpentry  work,  this  branch  should  be  reviewed 
again  on  all  the  drawings  to  see  that  everything  has  been 
included.  Words  known  as  localisms  should  be  avoided,  which 
are  used  and  clearly  understood  only  in  certain  districts  and  by 
local  residents,  for  elsewhere  the  meaning  may  not  be  known. 
When  general  requirements  are  well  covered,  special  features 
and  details  should  be  explained  and  particularly  those  which 
are  not  easily  shown  on  the  plans.  Uncertain  features  may 
sometimes  be  covered  by  "blanket  clauses"  or  comprehensive 
statements.  For  the  sake  of  clearness,  it  is  better  that  all  notes 
on  the  drawings  be  repeated  in  the  specifications. 


CHAPTER  VI 
SELECTION  QF  BUILDING  TYPE 

The  primary  object  of  factory  buildings  is  financial  profit, 
and  in  this  respect  they  differ  from  houses  or  monumental 
structures,  which,  in  addition  to  utility,  are  for-  comfort  and 
beauty.  Manufacturing  buildings  are  merely  supplementary 
to  their  contents  and  all  the  plans  should  be  developed  together, 
the  buildings  forming  a  convenient  enclosure  of  the  right  size 
and  form,  for  the  machinery  within.  Capital  is  more  easily 
secured  for  the  erection  of  buildings  of  regular  form  than  for  irreg- 
ular ones,  because  those  of  the  former  type  can  more  easily  be 
adapted  to  other  purposes  if  vacated  by  the  original  industry. 

Kind  of  Building  Material. — The  usual  types  of  factory  build- 
ings are: 

1.  Complete  wooden  buildings. 

2.  Slow  burning  or  mill  construction  framing  with  brick  walls. 

3.  Steel  frame  with  walls  of  brick  or  concrete. 

4.  Reinforced  concrete  frame  with  walls  of  brick  or  concrete. 
The  rule  is  to  select  that  type  in  which  work  can  be  done  with 

the  greatest  ease,  efficiency  and  security  at  the  least  ultimate 
cost,  when  interest,  insurance  and  depreciation  are  considered. 
The  extent  to  which  building  materials  will  affect  the  first  cost, 
depends  upon  their  selling  price  at  the  place  of  manufacture, 
with  transportation  charges  to  the  site  added,  and  the  facility 
for  receiving  and  hauling  them  when  they  arrive.  Preference 
will  often  be  given  for  that  material  which  is  near  at  hand  and 
therefore  more  quickly  obtained  at  a  lower  cost.  In  those 
Pacific  states  where  good  timber  is  still  plentiful,  it  is  much  used 
in  preference  to  steel,  which  must  usually  be  brought  a  long- 
distance— often  from  Pennsylvania  and  Ohio.  On  the  other 
hand,  in  the  vicinity  of  rolling  mills  and  structural  works,  steel 
framing  may  be  more  quickly  made  than  timber  and  at  nearly 
the  same  cost. 

Wood,  metal  and  concrete  framing  each  have  their  special 
merits  which  are  mentioned  elsewhere.  Exposed  metal  framing 
is  not  suitable  for  buildings  where  gases  or  sulphuric  acid  fumes 

52 


SELECTION  OF  BUILDING  TYPE  53 

are  generated,  as  in  locomotive  sheds,  gas  houses,  or  shops  for 
making  storage  batteries,  for  the  metal  is  rapidly  corroded  by  the 
fumes.  Reinforced  concrete  compares  favorably  in  cost  with 
timber,  for  buildings  of  several  stories  and  column  spacing  of 
16  to  20  feet,  with  floor  loads  of  250  Ibs.  per  square  foot  or  more. 
But  for  one  story  buildings  and  especially  those  with  long  spans, 
reinforced  concrete  for  framing  cannot  compare  in  cost  with 
steel.  Wood  sheathing  for  roofs  is  cheaper  in  first  cost  than  slabs 
of  reinforced  concrete. 

Essentials  of  Good  Framing. — The  essential  qualities  of  good 
framing  are: 

1.  Strength 

2.  Durability  or  endurance 

3.  Utility 

4.  Simplicity  of  construction 

5.  Economy 

6.  Possibility  of  quick  and  easy  erection. 

The  columns,  walls  and  floors  must  evidently  be  strong  enough 
to  carry  their  loads,  and  requirements  of  the  near  future  should 
be  anticipated,  for  the  strengthening  of  buildings  is  difficult  and 
expensive. 

Durability  or  endurance  depends  much  on  the  absence  of  vibra- 
tion, the  injurious  effect  of  which  is  very  great.  The  building 
must  also  resist  the  attacks  of  weather  and  the  elements,  and 
should  be  as  nearly  fireproof  as  possible. 

Utility  and  efficiency  are  secured  by  good  lighting,  heating  and 
ventilating,  together  with  cleanliness  and  sanitary  conditions. 

Simplicity,  quick  erection  and  economy  are  essentials,  factors 
of  economy  being  low  cost  of  construction,  maintenance  and 
operation. 

Vibration  and  Oscillation. — Vibration  is  a  local  shaking  of 
parts  under  loads  or  impact,  while  oscillation  is  the  swaying  of  the 
building  as  a  whole,  resulting  from  the  movement  of  cranes  or 
machinery  acting  in  unison.  Both  of  these  cause  serious  injury 
to  the  framing  with  frequent  breaking  of  skylights  and  windows. 
These  movements  also  cause  excessive  wear  on  machines  and 
necessitate  a  greater  amount  of  power  to  run  them.  Oscillation 
often  occurs  in  steel  frame  buildings  of  several  stories  with  brick 
exterior  walls,  which  are  used  for  such  purposes  as  printing  and 
binding,  a  notable  one  of  seven  stories  in  Chicago  having  a  move- 
ment at  the  top  of  several  inches,  even  though  the  five-story 


54       ENGINEERING  OF  SHOPS  AND  FACTORIES 


building  adjoining  it  is  made  of  concrete.  Recent  inspection  of 
this  building  by  the  writer  showed  that  such  excessive  oscillation 
had  a  serious  effect  on  the  occupants,  particularly  on  occasional 
visitors  unaccustomed  to  its  movement.  In  a  plant  valued  at 
$100,000  it  has  been  estimated  that  the  cost  of  machinery  repairs 
from  vibration  alone  would  average  one  to  two  dollars  per  day. 

Depreciation. — Yearly  depreciation*  depends  upon  the  ultimate 
duration  of  a  building,  and  its  scrap  value  at  the  conclusion  of 
that  period.  Slow  depreciation  usually  accompanies  high  first 
cost,  and  rapid  depreciation  low  first  cost,  though  there  are  ex- 
ceptions to  the  rule.  Wooden  buildings  of  slow  burning  con- 
struction have  a  yearly  depreciation  of  1  to  H  per  cent., 
while  those  of  reinforced  concrete  do  not  exceed  J  of  1  per  cent. 

Insurance. — The  need  of  fireproof  construction  is  evident,  when 
the  annual  fire  loss  is  considered,  which  in  the  United  States 
alone,  exceeds  $250,000,000,  or  $2.50  each  year  for  every  person. 

Insurance  rates  vary  considerably  according  to  the  time  and 
place  and  to  the  available  water  supply  and  fire  protection. 
Approximate  annual  insurance  charges  on  buildings  of  different 
types  for  city  location,  but  without  sprinkler  systems,  are  given 
in  the  following  table.  The  figures  are  the  rates  of  insurance  in 
cents  per  $100  of  value  for  both  building  and  contents. 

TABLE  I.— APPROXIMATE  INSURANCE  CHARGES 


Wood  mill 

Wood  mill 

Concrete  bldg. 

constr.,  brick 

constr.,  wood 

sides 

sides 

Bldg. 

Contents 

Bldg. 

Contents 

Bldg. 

Contents 

General  storehouse  

20 

45 

60 

100 

100 

125 

Wool  warehouse  

20 

35 

40 

60 

75 

100 

Office  

15 

30 

35 

50 

100 

125 

Cotton  factory  

40 

100 

100 

200 

200 

300 

Tannery  

20 

40 

75 

100 

100 

100 

Shoe  factory     

25 

80 

75 

100 

150 

200 

Woolen  mill  

30 

80 

75 

100 

150 

200 

Machine  shop  

15 

25 

50 

50 

100 

100 

Merchandise  building.  .  .  ]     35 

75 

50 

100 

100 

150 

Paper  factory 

12 

29 

21 

65 

Average  

10-40 

30-70 

20-75 

60-100 

75-150 

100-200 

SELECTION  OF  BUILDING  TYPE 


55 


TABLE  II.— INSURANCE  CHARGES  REPORTED  BY  ANOTHER  COMPANY 
ARE  AS  FOLLOWS: 


Concrete  bldg. 

Wood  mill 
constr.,  brick 
sides 

Brick  and  steel 
construction 

Building 

Contents 

Building  and 
contents 

Building  and 
contents 

Pattern  storage  bldg. 
Foundry 

25-50 
30-65 
25-50 

45-65 
65-100 
50-75 

85 
135 
100 

70 
115 

85 

Machine  shop  

Buildings  for  Merrit  &  Co.  of  Philadelphia  had,  in  1907,  insur- 
ance rates  per  $100  of  value  for  building  and  contents  of 

182  cents  per  $100,  for  reinforced  concrete  buildings, 
357  cents  per  $100,  for  mill  construction  buildings. 
All  of  the  above  charges  are  for  buildings  without  automatic 
sprinkler  systems.  When  these  are  installed,  the  charges  are 
reduced  by  50  to  75  per  cent.  Reports  published  in  1908  show 
that  the  rate  of  insurance  on  buildings  of  mill  construction, 
reinforced  concrete,  or  steel  frames  not  fireproof ed,  when  "pro- 
vided with  automatic  sprinkler  systems,  is  20  to  35  cents  per 
$100  per  year. 


FIG.  20. 

Roof  Outline. — The  exterior  roof  outline  should  be  such  as  to 
shed  water,  and  if  necessary,  to  admit  light  and  air,  but  it  should 
also  be  of  pleasing  appearance.  These  results  are  obtained  in 
many  ways,  some  of  which  are,  by  double  pitch  roofs  with  center 
monitor  (Fig.  20),  transverse  monitors  on  flatter  pitches  (Fig. 
21),  and  single  slopes  with  light  admitted  from  the  north  side 
only  (Fig.  22) .  A  double  pitch  roof  with  a  center  monitor  is  an 


56       ENGINEERING  OF  SHOPS  AND  FACTORIES 

excellent  outline  as  far  as  water  shedding,  ventilation,  and 
appearance  is  concerned,  but  it  fails  in  admitting  sufficient  light. 
Windows  on  narrow  monitors  throw  but  little  light  to  the  floor, 
and  glass  skylights  must  usually  be  placed  on  the  roof.  Sky- 
lights are  often  undesirable  in  single  story  metal  working  shops, 


FIG.  23. 


FIG.  24. 


Glass 


FIG.  25. 

as  they  are  frequently  broken  from  the  action  of  cranes.  The 
insufficient  light  from  windows  on  longitudinal  monitors  is  due 
chiefly  to  the  narrow  monitor  widths  (Fig.  23),  which  rarely 
exceed  5  to  10  ft.,  and  for  this  reason  some  recent  shops  have 
roofs  with  moderately  flat  pitch,  and  transverse  monitors 


SELECTION  OF  BUILDING  TYPE 


57 


covering  the  whole  width  of  alternate  panels,  their  sides  being 
covered  with  movable  sash.  When  these  cross  monitors  inclose 
pairs  of  adjoining  trusses  (Fig.  24),  there  is  economy  of  interior 
heating  space  as  the  roof  outline  lies  just  above  the  lower  and 
upper  truss  chords  on  which  the  purlins  are  supported.  A  good 
example  of  this  type,  is  a  pattern  shop  recently  erected  for  the 
Maryland  Steel  Company.  Instead  of  covering  alternate  roof 
bays,  the  transverse  monitors  may  be  placed  at  less  frequent  in- 
tervals, and  may  extend  either  part  way  or  entirely  across  the 
roof.  Transverse  monitors  over  every  third  roof  panel,  the 
monitor  sides  being  covered  with  glass,  give  good  lighting  effect. 
With  panel  lengths  of  20  ft.  and  cross  monitors  over  every  third 
panel  the  cost  of  the  two  types  will  be  about  the  same  when  the 


FIG.  26. — Truss  outline  for  effective  roof  lighting. 

length  of  the  cross  monitor  is  60  ft.  or  equal  to  three  panels. 
Longitudinal  monitors  for  lighting  should  have  a  width  of  about 
one  quarter  of  the  span,  but  when  for  ventilation  only  a  less 
width  is  preferable. 

Another  plan, is  to  use  flat  pitch  roofs  over  the  central  part  of 
the  building,  with  end  posts  of  the  trusses  near  the  walls,  inclined 
at  angles  of  about  45  degrees,  these  side  sloping  areas  being 
covered  with  glass  (Fig.  25).  This  position  and  inclination  of 
glass  is  excellent  for  admitting  light,  but  the  sloping  sash  are 
liable  to  leak. 

As  warm  air,  gas  and  smoke  naturally  rise  to  the  highest  level, 
they  can  be  withdrawn  only  when  ventilators  are  at  the  summit, 
and  roofs  with  double  pitch  descending  from  the  center  to  the 
side  must  therefore  have  the  monitor  at  the  ridge.  But  as 
previously  stated,  this  form  admits  insufficient  light  through  the 
monitor  sides.  The  outline  may,  therefore,  be  reversed,  and  a 


58       ENGINEERING  OF  SHOPS  AND  FACTORIES 

longitudinal  gutter  placed  over  the  center  of  the  building  with  a 
double-pitch  roof  ascending  to  the  sides  (Fig.  26) ,  giving  greater 
window  height  for  light  and  ventilation.  Sash  can  stand  vertical, 
and  objectionable  sloping  skylights  can  be  avoided.  Ventilation 
is  effective  without  any  fire  risk  when  these  sash  are  made  of 
rolled  steel  and  operated  in  clusters  (Fig.  27).  This  type  of 


Clip  and  Angle 
furnished  by 
Steel  Contractor 


Drip  Hole 


•  Furnished  by  other  Contractors 

FIG.  27. — Detail  of  sash  for  northern  light  roofs. 

roof  fulfills  all  useful  purposes  but  is  lacking  in  esthetic  outline. 
North  light  roofs,  like  many  other  comparatively  new  things, 
have  been  used  to  excess,  and  often  with  insufficient  reason. 
Their  chief  advantage  is  that  sunlight  is  not  admitted  and 
shadows  are  therefore  avoided.  They  have  the  objection  of 


SELECTION  OF  BUILDING  TYPE 


59 


increased    cost    and    poorer    ventilation.     Some    recent    metal 
working  shops  with  three  longitudinal  bays — the  central  one  for. 


FIG.  28. 


Glass- 


Glass  this 
!  Side  only 


FIG.  29. 


FIG.  30. 


erection  being  higher  than  the  sides,  have  transverse  saw-tooth 
roofs  over  all  of  the  bays,  while  other  shops  use  saw-tooth  over 


FIG.  31. — Shed  with  single  gable. 

the  side  bays  only,  with  a  double-pitch  roof  in  the  middle. 
There  is  little  or  no  difference  in  the  cost  between  vertical  or 


FIG.  32. — Building  with  double  gable. 

inclined  surfaces  for  the  north  windows,  for  while  vertical  faces 
give  a  greater  area  to  be  covered,  the  cost  of  framing  and  opening 


60       ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  windows  is  less.     The  greater  cost  of  vertical  sides  is,  there- 
fore, offset  by  the  less  cost  of  windows  (Fig.  28). 

North  roof  light  may  be  admitted  to  buildings  with  widths  of 
60  ft.  or  less,  by  placing  a  single  longitudinal  monitor  over  the 
whole  length  of  the  building,  with  glass  on  the  north  side  only. 
This  monitor  may  take  the  form  of  a  saw-tooth  (Fig.  29) ,  or  may 


FIG.  33. — Market  building  around  an  open  square. 

be  symmetrical  with  vertical  faces  on  both  sides,  and  the  south 
face  covered  with  sheathing  (Fig.  30) .  An  example  of  this  kind 
with  saw-tooth  monitor  may  be  seen  in  the  new  two-story  con- 
crete shop  at  Cornell  University. 

Buildings  may  have  either  one  ridge  (Fig.  31),  or  two  (Fig. 
32),  or  may  be  built  around  an  open  square  (Fig.  33),  a  form 
which  is  especially  suitable  for  market  buildings  where  an  abund- 
ance of  fresh  air  is  needed. 


CHAPTER  VII 
WOOD  AND  METAL  FRAMING 

Timber  as  a  structural  material,  has  lately  received  whole- 
sale condemnation  by  those  who  are  commercially  interested  in 
reinforced  concrete,  but  the  real  cause  for  a  decreasing  use  of 


UvJ ro> - 

End  Post  and  Bottom  Chord  Connection. 


s-16'0* 


Nailing  of  Top  Chord 
3410"-, , 


Nailing   of  Bonom  Chord 
Details  in  Top  and  Bottom  Chords. 


s  not  shown  are  designated  by 
n  number  and  ju>e.  thus:  16-SOd. 


-J 


7f  rmedtare  Studding  2'0'c.  roc. 


5-6"*6"x4'0" 
"*I2'*4'O' 

Half  Transverse  Secrional  Elevation 


4W*BW(. 


I8'O' 


Side  Elevation  of  One  Panel 

FIG.  34. — Timber  framing  for  auditorium  at  Seattle. 


61 


62       ENGINEERING  OF  SHOPS  AND  FACTORIES 

timber  is  not  its  lack  of  merit,  but  rather  the  difficulty  of  secur- 
ing it  in  working  lengths  and  at  a  reasonable  cost.  Notwith- 
standing the  increased  use  of  steel  and  reinforced  concrete,  the 
continued  importance  of  timber  in  construction  is  shown  by  a 
recent  report  of  the  United  States  Geological  Survey,  covering 
forty-nine  American  cities.  From  this  report  it  appears  that  tim- 


FIG.  35. 

ber  still  constitutes  61  per  cent,  of  all  structural  material  with 
only  39  per  cent,  of  other  materials.  In  the  New  England  States 
more  mills  are  framed  of  wood  than  of  all  other  materials  combined. 
Timber  has  a  low  first  cost,  is  easily  framed,  and  is  often  pre- 
ferred especially  in  the  South  and  West  where  it  is  still  plentiful. 
The  objection  to  timber  is  its  fire  risk  and  corresponding  insur- 
ance charges.  Its  general  use  on  the  Pacific  coast  is  shown  by 


WOOD  AND  METAL  FRAMING 


63 


such  buildings  as  the  large  skating  rink  at  San  Francisco  with 
trusses  170  ft.  long,  the  auditorium  at  Venice,  California,  and  a 
large  one  at  Seattle  with  a  span  of  96  ft.  (Fig.  34).  The  rink  at 
San  Francisco  has  bents  20  ft.  apart,  with  a  roof  pitch  of  1  in 
3£,  and  bottom  chords  in  the  segment  of  a  circle.  Trusses  are 
of  Oregon  pine  planks,  and  the  total  roof  weight,  including, 
trusses,  purlins  and  corrugated  iron  is  10  Ib.  per  square  foot. 
Figs.  35  and  36  show  other  details  of  timber  framing. 

Even  in  the  East  and  Middle  States,  timber  is  still  often  favored 
as  evidenced  by  the  erection  in  1907,  of  a  roof  over  the  Elysium 


-Oak  Packing 


^Oak  Splice. 

FIG.  36. 


skating  rink  at  Cleveland,  with  wooden  arch  trusses  of  100-ft. 
span.  When  provided  with  automatic  sprinklers,  cut  off  walls, 
and  fire  extinguishers,  slow  burning  construction  with  large  size 
timbers,  though  not  fireproof,  is  considered  a  good  fire  risk,  for 
the  action  of  fire  on  large  timbers  is  slow. 

Trusses  are  easily  framed  by  making  chords  of  several  layers 
of  plank  spiked  together,  with  main  web  diagonals  of  solid 
timber,  and  counters  of  double  2  to  3-in.  planks  inserted  for  the 
sake  of  better  joints,  between  the  layers  of  plank  in  the  chords. 
The  number  of  spikes  or  nails  of  different  size  needed  at  the 
joints,  may  be  computed  from  the  following  table: 


64       ENGINEERING  OF  SHOPS  AND  FACTORIES 

TABLE  III.— SHEARING  VALUE  IN  LBS.  OF  NAILED  JOINTS. 


Ultimate 

Resistance  at 
yield  point 

30  d  wire  nail  

460 

230 

For  working  unit 

40  d  wire  nail  .  .    

.    560 

280 

use  half   of   this 

50  d  wire  nail  .  

650 

•*    325 

last    column,    or 

60  d  wire  nail  

750 

375 

a  quarter  of  the 

7  in.  wire  nail,  gauge    0  

1070 

535 

ultimate. 

8  in.  wire  nail,  gauge  00  

1290 

645 

I. 

Columns  should  be  of  good  straight  timber  without  knots,  the 
best  kind  being  Southern  pine.     They  should  be  bored  through 


FIG.  37a. — Details  of  timber  framing. 

the  center  with  a  IJ-in.  hole  and  should  remain  unpainted  for 
about  two  years.     Columns  supporting  floors  must  usually  be 


FIG.  376. — Iron  caps  and  base  for  wooden  columns. 

spaced  not  more  than  12  to  16  ft.  apart,  owing  to  the  increasing 
difficulty  in  get'ting  greater  lengths.  Timber  columns  were 
often  designed  with  excessive  strength  and  dimensions,  but  they 
should  now  be  proportioned  by  Professor  Lanza's  formulae  or 
some  other  one  equally  reliable. 


WOOD  AND  METAL  FRAMING 


65 


Details  of  column  and  beam  connections  are  shown  in  Figs. 
37  and  38. 

Floor  timbers  bearing  on  walls  should  be  anchored  thereto 
with  flanged  bearing  plates,  and  not  as  formerly,  with  bolts  pass- 
ing through  the  walls  fastened  outside  with  washers,  because  the 
latter  arrangement  in  case  of  fire,  causes  the  wall  to  collapse. 
An  excellent  floor  is  made  of  2  by  4,  or  2  by  6-in.  scantling  laid 
on  edge  and  spiked  together,  and  covered  with  a  wearing  surface 
of  1-in.  flooring.  (See  Wood  Floors). 


FIG.  38. — Beam  hangers. 

To  prevent  fire  from  passing  up  to  other  stories,  belt  towers 
should  be  separated  from  the  working  floors  by  brick  partitions 
with  fire  doors.  Without  such  towers  fire  was  formerly  carried 
up  through  the  building  on  belts. 

Cost  of  Wood  Mill  Construction. — Buildings  of  slow  burning 
wood  construction,  in  widths  of  about  50  ft.  and  heights  up  to 
five  or  six  stories,  cost  in  the  Northern  States  about  as  follows: 


Number  of  stories 

Cost  in  cents 
per  square  foot  of 
floor  area 

Cost  in  cents 
per  cubic  foot  of 
contents 

3  4  or  5  stories  

85  to  95 

6  .  5  to  7  .  5 

2  story 

90  to  100 

7  0  to  8  0 

95  to  105 

7.5  to8.5 

These  costs  do  not  include  plumbing,  heating,  or  elevators,  which 
would  increase  the  cost  by  1  to  2  cents  per  cubic  foot  in  each 

5 


66       ENGINEERING  OF  SHOPS  AND  FACTORIES 


case.  In  country  districts  where  labor  is  cheap,  the  cost  may  be 
15  to  20  per  cent,  less,  and  in  the  South,  where  both  labor  and 
materials  are  30  to  50  per  cent,  less  than  in  the  North,  the  cost 
will  be  reduced  accordingly.  Buildings  which  cost  8^  cents 
per  cubic  foot  in  large  cities,  have  been  reproduced  in  small 

^  towns  for  about  6  cents 
per    cubic    foot.     Under 
T  the  most  favorable  con- 
ditions,    wood      factory 
buildings    in  the  South, 
not  including   the  items 
;-  mentioned     above,     will 
cost   as    low  as   4|  to  5 
cents  per  cubic  foot.     In 
Georgia    and      Carolina, 


E 

12x2 

11 
)"} 

.r 

p. 

T 

1 

I 

1 

[ 

] 

[ 

] 

[ 

J 

[ 

] 

D 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

\ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

D 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

3 

t 

] 

D 

[ 

] 

t 

] 

[ 

] 

[ 

] 

[ 

] 

t 

] 

[ 

] 

[ 

] 

t 

] 

n 

[ 

] 

[ 

] 

( 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

D 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

D 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

] 

[ 

i 

t 

] 

n 

t 

i 

t 

i 

[ 

: 

t 

i 

c 

] 

======] 

D  n 

D  a 

D  0 

D  D 

as 

D  H 

D  D 

D  a 

ftt  D 

D  D 

D  DH 

fl  D 

D  D 

D  3 

d  D 

D  D 

D  t| 

D  D 

D   D 

D  g 

D   D 

FIG.  39. — Seven  story  factory  at  Cincinnati,  Ohio. 

two-story  cotton  mills  have  occasionally  been  erected  at  prices 
of  45  to  60  cents  per  square  foot  of  floor  area.  The  building 
costs  given  above  for  northern  latitudes  are  quite  low,  and  wooden 
buildings  of  mill  construction  with  floorloads  of  200  Ib.  per  square 
foot,  have  sometimes  cost  from  $1.40  to  $1.60  per  square  foot. 

A  slow  burning  wood  mill  building  (Fig.  39)  designed  in  1905 
by  the  writer,  with  a  basement  and  seven  stories,  and  a  total 
floor  area  of  38,700  sq.  ft.,  cost  for  the  structure  only,  with 
foundations,  floors  and  framing,  but  without  equipment,  96 
cents  per  square  foot  of  floor  area,  and  7.7  cents  per  cubic  foot 


WOOD  AND  METAL  FRAMING 


67 


of  contents.  It  was  proportioned  for  a  live  load  of  200  Ib.  per 
foot  on  the  floors.  Another  six-story  building1  60  ft.  wide  and 
100  ft.  long,  for  a  floor  load  of  only  100  lb.,  cost  83  cents  per 
square  foot,  or  6.2  cents  per  cubic  foot,  the  cost  of  the  floors  and 
columns  only,  being  27  cents  per  square  foot  of  floor  area. 
A  table  giving  the  cost  of  a  miscellaneous  lot  of  wood  build- 
ings, reproduced  from  a  report  of  the  National  Association  of 
Cement  Users  for  1909,  is  as  follows: 

TABLE   IV.— COST  OF   BUILDINGS   OF   WOOD  MILL 
CONSTRUCTION 


Cost 

Vol. 

Floor  area 

Uni1 

V 

LJ  cost 

cu.  ft. 

sq.  ft. 

cu.  ft. 

sq.  ft. 

Mill  Boston 

$  66,516 

544,788 

44  172 

122 

1  51 

Warehouse,  Boston  
Mill  Boston 

337,000 
113,288 

2,808,850 
,271,300 

129,920 

.12 
0891 

875 

Storehouse,  Nashua  
Mill,  Easthampton  
Mill,  Fitchburg  
Mill,  Woonsocket 

101,098 
90,706 
72,048 
85,754 

,714,450 
,622,128 
,331,200 
,752,600 

168,696 
152,200 
83,200 
81,500 

.059 
.056 
.054 
048 

.60 
.60 
.865 
1  05 

Mill,  Centerville  
Mill,  Pawtucket 

122,128 
94,341 

2,641,000 
2,036,700 

98,059 
174,000 

.046 
046 

1.25 
542 

Mill,  Fitchburg  
Average  cost     .  .  . 

129,400 

2,867,500 

157,700 

.045 
069 

.82 
90 

From  this  table  it  appears  that  the  cost  of  these  buildings  per 
cubic  foot  varies  from  4J  to  12  cents,  with  an  average  of  about 
7  cents,  and  the  corresponding  cost  per  square  foot  of  floor  area, 
from  54  cents  to  $1.50,  with  an  average  of  90  cents. 

The  cost  is  affected  also  by  the  degree  of  duplication  which  is 
carried  out,  and  by  the  simplicity  of  the  framing.  It  is  usually 
economical  to  specify  lengths  and  sizes  which  are  easily  obtainable, 
for  if  extra  ones  are  desired,  the  cost  will  be  increased  with  accom- 
panying delay.  As  previously  stated,  the  cost  of  wood  framing 
depends  upon  the  location.  Timber  which  would  cost  $28  to  $30 
per  M  at  Chicago,  might  be  purchased  in  Oregon  for  about  half 
those  prices,  the  delivered  price  being  a  combination  of  the  pro- 
duction cost  and  profit,  with  freight  charges  added. 

Corresponding  charts  for  the  cost  of  wood  mill  buildings,  pre- 
pared by  C.  T.  Main  of  Boston,  are  as  follows: 

1  H.  G.  Tyrrell,  in  Carpentry  and  Building,  Nov.,  1905. 


68       ENGINEERING  OF  SHOPS  AND  FACTORIES 


0      50      100     150     200    250    300    350    400   450    500 
Length  in  ft . 

FIG.  40. — Cost  diagram  for  brick  mill  buildings,  one-story. 


°-70  """o"    o  150  ZOQ  250  300  350  400  450  500 
Length  in  ft. 

FIG.  41. — Cost  diagram  for  brick  mill  buildings,  two-story. 


WOOD  AND  METAL  FRAMING 


69 


50      100     150    ZOO    Z50    300    350   400    450    500 
Length  in  fr. 

FIG.  42. — Cost  diagram  for  brick  mill  buildings,  three-story. 


50      100      150     200     250     300    350     400     450     500 
Length  in  fK 

FIG.  43. — Cost  diagram  for  brick  mill  buildings,  four-story. 


70       ENGINEERING  OF  SHOPS  AND  FACTORIES 


2.10 
2.00 
L90 
1.80 
1.70 


0      -5C      100     150     200    250   300    350   400    450-    500 
Length  in  ft. 

FIG.  44. — Cost  diagram  for  brick  mill  buildings,  five-story. 


0.70. 


1  '  '  '  'I *••*  I  *  '  *  I  I  *  I  I  i  I  I  I  I  I  I  i  I  I  I  I  I  I,  IJ 

0       50      100      150     200    250     300     350    400    450     500  ? 
Length  in  ft, 

FIG.  45. — Cost  diagram  for  brick  mill  buildings,  six-story. 


WOOD  AND  METAL  FRAMING 


71 


Metal  Framing. — Steel  framing  can  be  definitely  proportioned 
for  either  short  or  long  spans,  with  connections  of  any  desired 
strength,  and  it  can  be  quickly  erected.  It  is  not  fireproof  and 
deteriorates  rapidly  from  rust  when  not  painted  or  not  otherwise 
protected.  It  has  been  conclusively  proven  by  great  conflagra- 
tions such  as  those  at  San  Francisco  and  Baltimore,  that  steel 
is  not  fireproof  or  permanent  even  when  enclosed,  for  the  covering 
will  break  off,  leaving  the  metal  exposed.  At  a  temperature  of 
1000°  F.,  steel  framing  will  collapse  under  load,  resulting  in 
complete  ruin.  A  casing  or  enclosure  of  1/2  to  2  in.  of  rein- 
forced concrete  gives  partial  protection,  but  is  of  little  use  when 
fire  has  gained  much  headway.  Fireproofing  with  terra  cotta 
blocks  is  of  still  smaller  value,  as  the  blocks  are  brittle  and  will 
shake  to  pieces.  Steel  framing  is  not  considered  even  as  choice 
a  fire  risk  as  heavy  timbers,  and  it  costs  including  maintenance, 
much  more  than  either  timber  or  reinforced  concrete. 

Cast  iron  columns  are  often  preferable  to  steel,  for  they  oc- 
cupy smaller  space  and  have  a  better  appearance,  but  they  fail 
quickly  in  fire  when  cooled  with  a  jet  of  water,  though  not  so 
quickly  as  steel.  Unless  the  casting  process  is  carefully  done, 
the  core  is  liable  to  float,  making  the  metal  thinner  on  one  side  of 
the  columns  than  on  the  other,  and  in  this  condition  they  may  be 
unsafe  and  liable  to  fail  under  lateral  blows  or  pressure.  De- 
fects of  this  kind  can  be  detected  only  by  measuring  the  thickness 
with  a  long  arm  calipers,  but  danger  can  be  avoided  by  using 
columns  of  wrought-iron  pipe,  the 
strength  of  which  can  be  increased 
by  filling  them  with  fine  concrete. 
Rolled  steel  columns  of  Bethelehem 
shape  (Fig.  46),  save  the  expense  of 
punching  and  riveting,  and  connec- 
tions to  them  are  easily  made,  but 
this  saving  is  somewhat  offset  by 
their  greater  pound  price. 

Metal     frames     are     preserved    in 
several   ways,    some    of   which    are: 
(1)  painting,  (2)  Bower-Barff  oxida- 
tion,   (3)    zinc   or    lead    coating,    and    (4)   enameling.     In  the 
Bower-Barff  process,  superheated  steam  is  passed  over  metal 
while   it   is  red  hot,  when  oxygen  combines  with  the  metal, 
forming  an  oxide  coating  which  prevents  any  further  oxidation. 


FIG.  46. 


72       ENGINEERING  OF  SHOPS  AND  FACTORIES 


Cross  Section 


FIG.  47. — Machine  shop  at  Lynn,  Mass. 


****vi 


^ 


Floors 

h  F/oqr 


FIG.  48. — Spinning  mill  at  New  Bedford,  Mass. 


WOOD  AND  METAL  FRAMING 


73 


A  three-story  shop  with  metal  framing  and  steel  columns  is 
shown  in  Fig.  47,  and  a  four-story  shop  of  unusual  width  in 
Fig.  48.  Fig.  49  is  a  typical  floor  plan  of  the  ten-story  Everard 
warehouse  at  10th  and  Washington  streets,  New  York,  plans  for 


(HZ'L&>ZO.SJbr9^to  If- floors 
-I      (\]-lS"L036* for Stf-oS* floors 


FIG.  49. — Typical  floor  plan,  Everard  warehouse,  New  York  City. 

which  were  made  by  the  writer  in  1896,  and  the  accompanying 
table  gives  a  schedule  of  the  columns.  In  order  to  add  stiffness 
to  the  frame,  the  column  sections  generally  extend  through  at 
least  two  stories,  and  column  splices  are  staggered,  some  splices 


74       ENGINEERING  OF  SHOPS  AND  FACTORIES 


NOTE. — The  column  schedule  given  herewith  is  much  more  lengthy  than  was  intended  by 
the  author,  but  it  may  be  valuable  to  students  and  others  not  regularly  engaged  in  design- 
ing building  frames,  and  especially  so  as  such  data  is  not  generally  found  in  other  books. 

SCHEDULE  OF  COLUMNS 


Floor 

Height 
between 
floors 

Col.  No.  1 

Col.  No.  2 

Col.  No.  3 

Col.  No.  4 

Twelfth.. 

4  Ls.  2*X2  XI" 
1P1.  6Xi" 

Eleventh. 

10'  3" 

4Zs.  3  X  i" 

Tenth.  .  .  . 

10'  3" 

1  PI.  6XJ" 

Ninth.... 

10'  3" 

4Zs.  5Xf" 

Eighth.  .  . 

10'  3" 

1  PI.  7X1" 

Seventh.  . 

10'  3" 

4  Zs.  6  X  \" 

i-H 

6 

£ 

6 

^ 

Sixth  

10'  3" 

1  PI.  8Xi" 

§ 
|- 

§ 
§ 

s 

1 

Fifth  

10'  3" 

4  Zs.  6XH" 

0> 

•    1 

m 

0) 

eo 

Fourth.  .  . 

10'  3" 

1  PI.  8XH" 

Third.... 

10'  3" 

4Zs.  6X1" 

Second..  . 

,    .    .    . 
10'  3" 

1   1  PL  8X1" 

J 

First  

12'  0" 

2  Pis.   14  Xf" 
4  Zs.  6X1" 
1P1.  8X|" 

Cellar.  .  .  . 

1 
12'  6" 

1  PI.  8X1" 
2  Pis.  14  Xi" 
4Zs6X|" 

WOOD  AND  METAL  FRAMING 


75 


SCHEDULE  OF  COLUMNS— Continued 


Height 

Floor       between         Col.  No.  5  Col.  No.  6  Col.  No.  7  Col.  No.  8 

floors 


Twelfth 

. 

4  Ls  2*X2Xi" 

4Ls.  2*X2Xl" 

1P1.  6X1" 

Eleventh: 

10'  3" 

1  PI.  6X1" 

I 

4Zs.  3X1" 

Tenth.  .  .  . 

10'  3" 

I 

1  PI.  6X1" 

J 

Ninth.  .  .  . 

10'  3" 

s 

4Zs.  4Xf" 

Eighth.  .  . 

10'  3" 

^ 

i 

1P1.  6iXf" 

J 

Seventh.  . 

10'  3" 

6 

CO 

6 

4  ZS.  6  X  T7e" 

Sixth.  .  .  . 

10'  3" 

*o 
O 

a 

4  Zs.  4X1" 

§ 

a 

1  PL  8XiV 

Fifth  

10'  3" 

0 

1  PI.  6iXl" 
J 

• 

4  Zs.  6Xf" 

Fourth.  .  . 

10'  3" 

4  Zs.  4  X  A" 

1  PL  8X1" 

Third.... 

10'  3" 

1P1.  6JXA" 

1 

4  Zs.  6X12" 

Second.  .  . 

10'  3" 

4  Zs.  5X1" 

1  PL  8Xli" 

First  

12'  0" 

1P1.  7Xt" 

4Zs6XiJ" 
1  PL  8XU" 
2  Pis.  14  Xf" 

Cellar.... 

12'  6" 

4  Zs.  6X1J" 
1  PL  8XU" 
2  PL  14  X  ,V 

76       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  9 

Col.  No.  10 

Col.  No.  11 

Col.  No.  12 

Twelfth.. 

4Ls.  2iX2Xl" 
1  PI.  6iXi" 

•> 

4Ls.  2iX2Xl" 
1  PL  6Xi" 

Eleventh. 

10'  3" 

4  Zs.  4X1" 

4  Zs.  3  X  1" 

| 

Tenth.  .  .  . 

10'  3" 

1  PI.  6*  XI" 

1  PL  6  X  1" 

Ninth.  .  .  . 

10'  3" 

4Zs.  6Xf" 

4  Zs.  5  X  &" 

Eighth.  .  . 

10'  3" 

1P1.  8X1" 

1  PL  7XjV 

Seventh.  . 

10'  3" 

4  Zs.  6  X  ft" 

4  Zs.  ex/e" 

d 
«M 

6 

6 
6 

Sixth  

10'  3" 

1  PI.  8XTV' 

1  PL  8X&" 

^ 

§ 
§ 

fc 

3 
a 

Fifth  

10'  3" 

4  Zs.  6XH" 

4  Zs.  6X|" 

1 

s 

i 

Fourth.  .  . 

10'  3" 

1  PL  8  X  }1" 

1  PL  8  X  f" 

Third  

10'  3" 

4  Zs.  6X1" 

4  Zs.  6X}i" 

Second..  . 

10'  3" 

1  PI.  8X1" 
2  Pis.  14XTBS" 

1  PL  8Xii" 

First  

12'  0" 

2  Pis.  14  Xf" 
1  PI.  8X1" 

4  Zs.  6XF' 

4  Zs.  6X1" 

Cellar.  .  .  . 

12'  6" 

1P1.8X*" 
2  Pis.  14  Xi" 
4Zs6X£ 

1  PL  8X1" 
2  Pis.  14XrV 

WOOD  AND  METAL  FRAMING 


77 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  13 

Col.  No.  14 

Col.  No.  15 

Col.  No.  16 

Twelfth 

4Ls.2iX2Xl" 

4Ls.  2JX2X1" 
1  PL  6i  X  1" 

4Ls.  2JX2X1" 
1  PL  6$X&" 

Eleventh: 

10'  3" 

1  PL  6X1" 

4  Zs.  4X1" 

4Zs.  4XiV 

Tenth.  .  .  . 

10'  3" 

4  Zs.  3  X  1" 

lP1.6iXl" 

1  PL  6iX&" 

Ninth.... 

10'  3" 

1  PL  6  X  1" 

4Zs.  5X1" 

4  Zs.  6  X  i7s" 

Eighth.  .  . 

10'  3" 

4  Zs.  4  X  A" 

1  PL  7Xf" 

1  PL  8  X  iY' 

Seventh.  . 

10'  3" 

IPLOiXA" 

4Zs.  6Xi" 

4  Zs.  6XH'r 

10 
6 

Sixth.  .  .  . 

10'  3" 

4Zs.  5Xf" 

1P1.  8Xi" 

1PL  8XU" 

£\ 

3 
i 

Fifth  

10'  3" 

1  PL  7  Xf" 

4Zs.  6XH" 

4Zs.  6X4" 

0> 

Fourth.  .  . 

10'  3" 

4  Zs.  6XTY' 

1  PL  8XU" 

1  PL  8X4" 

Third.... 

10'  3" 

1P1.  SXjV 

4Zs.  6X}|" 

2  Pis.  14XTV 
1  PL  8  X  J" 
4  Zs.  6X|" 

Second.  .  . 

10'  3" 

4  Zs.  6  X  iV 

1  PL  8Xil" 

. 

1P1.8XI" 

2  Pis.  14XT98" 
4Zs.  6X1" 

First  

12'  0" 

1  PL  8  X  A" 

4  Zs.  6X£" 

2  Pis.  16  Xi' 
1  PL  10X1  ' 
4  Zs.  6X4' 

Cellar.  .  .  . 

12'  6" 

4  Zs.  6XH" 
1P1.8X1J" 

1  PL  8X4" 
2  Pis.  14X|" 

1  PL  10  X  1  ' 
2  Pis.  16  Xj' 
4Zs.  6X4' 

78       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  17 

Col.  No.  18 

Col.  No.  19 

Col.  No.  20 

Twelfth 

4Ls.2*X2Xi" 
1  PI.  7  X  A" 

j 

4Ls.2iX2Xj" 

Eleventh: 

10'  3" 

4  Zs.  5  X  ff" 

1  PL  6Xi" 

Tenth...  . 

10'  3" 

1  PI.  7  X  A" 

4Zs.  3Xi" 

Ninth.  .  .  . 

10'  3" 

4Zs.  6Xi" 

1  PL  6  X  i" 

Eighth.  .  . 

10'  3" 

1P1.  8Xi" 

4  Zs.  3  X  J" 

Seventh.  . 
Sixth.  .  .  . 

10'  3" 

»o 
6 

JO 

6 

4Zs.  6Xf" 

1  PL  6Xi" 

10'  3" 

I<                           'A 

§          § 

3            i             3 

1  PL  8X1" 
J 

4  Zs.  4XiV 

Fifth  

10'  3" 

0> 

1 

® 

4  Zs.  6X1" 

!P1.6iXA" 

Fourth.  .  . 

10'  3" 

1  PI.  8X1" 
2  Pis.  14  Xi" 

4Zs.  5XA" 

Third.... 

10'  3" 

2  Pis.  14X3y 
1  PI.  8  X  4" 
4  Zs.  6X1" 

1P1.7XA" 

Second.  .  . 

10'  3" 

1  PI.  8X1" 

2  Pis.  14  Xf" 
4  Zs.  6X1" 

4  Zs.  5  X  A" 

First  

12'  0" 

2  Pis.  18  X  i" 
1  PI.  12X1" 
4  Zs.  6X1" 

1  PL  7  X  A" 

J 

Cellar.  .  .  . 

12'  6" 

1  PI.  12X1" 
2  Pis.  18  X  f" 
4Zs.  6X1" 

4Zs.5Xf" 
1  PI.  7Xf" 

WOOD  AND  METAL  FRAMING 


79 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  21 

Col.  No.  22 

Col.  No.  23 

Col.  No.  24 

Twelfth.  . 

4Ls.  2*X2X1" 
1P1.  6Xi" 

4Ls.  2*X2X!" 
1P1.  6JXA" 

Eleventh 

10'  3" 

4Zs.  3X1" 
1  PI.  6X1" 

4  Zs.  4  X  A" 

Tenth...  . 

10'  3" 

4Zs.  5Xi" 

lP1.6iXA" 

Ninth.  .  .  . 

10'  3" 

1  PI.  7X1" 

|  4Zs.  5Xi" 

Eighth  .  .  . 

10'  3" 

4Zs.  6Xi" 

1P1.  7Xi" 

Seventh.  . 

10'  3" 

]  PI.  8Xi" 

4Zs.  6X|" 

si 

6 

% 

o 

Sixth.  .  .  . 

10'  3" 

4Zs.  6XH" 

1  PL  8X|" 

J 

fc 

3 
i 

S5 

§ 
a 

Fifth  

10'  3" 

1  PL  8X1J" 

4Zs.  6Xi§" 

02 

02 

Fourth.  .  . 

10'  3" 

4Zs.  6Xi" 

1P1.8XH" 

Third.... 

10'  3" 

1  PL  8X1" 

\ 

2  Pis.  14  X  A" 
1  PL  8X|" 
4  Zs.  6  X  f" 

Second.  .  . 

10'  3" 

}  2  Pis.  14  Xf" 
1  PL  8XJi" 
4  Zs.  6  X  !§" 

1  PL  8X1" 

2  Pis.  14XjV 
4Zs.  6Xi" 

First  

12'  0" 

1P1.  8Xli" 

"2  Pis.  14XTV 
4  Zs.  6Xii" 

2  Pis.  14X/6" 
1  PL  8X|i" 
4  Zs.  6X1;!" 

Cellar.  .  .  . 

12'  6" 

2  Pis.  14  X}£" 
4Zs.  6X[g" 
1P1.  8X}i" 

1  PL  8  X  12" 
2  Pis.  14Xf" 
4Zs.  6X11" 

80       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  25 

Col.  No.  26 

Col.  No.  27 

Col.  No.  28 

Twelfth.  . 

'                  ;••* 

Eleventh 

10'  3" 

i 

Tenth.  .  .  . 

10'  3" 

Ninth.... 

10'  3" 

Eighth.  .  . 

10'  3" 

Seventh.  . 

10'  3" 

8 

6 

S 

6 

•* 

6 

CO 

6 

Sixth  

10'  3" 

/H 

3 

% 

i< 

§ 

*£\ 

3 
1 

<\ 

~8 

§ 

Fifth  

10'  3" 

CO 

V 

0) 

O 

CO 

Fourth.  .  . 

10'  3" 

Third  

10'  3" 

2  Pis.  24  X  iV' 
2  Pis.  26  X  f" 
4Ls.  6X4X1" 
2  Pis.  13X|" 

Second.  .  . 

10'  3" 

2  Pis.  24  X  V 
2  Pis.  26  Xf" 
4Ls.  6X4X1" 
2  Pis.  13X|" 

First  

12'  0" 

'   2  Pis.  24  X  TV  ' 
2  Pis.  26X|" 
4Ls.  6X4X1" 
2  Pis.  13X|" 

+ 

Cellar.  .  .  . 

12'  6" 

2  Pis.  24  Xj" 
2  Pis.  26  X  f  " 
4Ls.  6X4Xf" 
2  Pis.  13Xf" 

WOOD  AND  METAL  FRAMING 


81 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  29 

Col.  No.  30 

Col.  No.  31 

Col.  No.  32 

Twelfth.  . 

4Ls.  21X2X1" 
1  PI.  6Xi" 

4Ls.  21X2XJ" 
1P1.  6lXi" 

Eleventh 

10'  3" 

4Zs.  3Xi" 
1P1.  6Xi" 

4Zs.  4X1" 
1  PL  6JX1" 

Tenth.  .  .  . 

10'  3" 

4Zs.  6Xf" 

4  Zs.  6  X  &" 

Ninth.... 

10'  3" 

1  PI.  8X|" 

1P1.8X&" 

Eighth.  .  . 

10'  3" 

4  Zs.  6X1" 

4Zs.  6Xf" 

Seventh.  . 

10'  3" 

1  PI.  8X1" 

J 

1  PI.  8Xf" 

g 

6 

6 

6 

Sixth  

10'  3" 

4Zs.  6X1" 

4Zs.  6X1" 

& 

s 

s 

l<^ 

3 

s 

Fifth  

10'  3" 

1P1.  8X1" 

1  PL  8X1" 
2  Pis.  14  X  A" 

a> 

V 

Fourth.  .  . 

10'  3" 

2  Pis.  14  X  TV 
1  PI.  8X1" 
4Zs.  6X1" 

2  Pis.  14XT9e" 

1  PI.  8  XI" 
4Zs.  6X1" 

Third.... 

10'  3" 

1  PI.  8X1" 

2  Pis.  14  X  t  " 

4Zs.6Xl" 

1  PL  8X1" 

2  Pis.  14  X  jt" 
4  Zs.  6  Xl" 

Second.  .  . 

10'  3" 

2  Pis.  16XiV' 

4Zs.  6X1" 
1P1.  10X1" 

2  Pis.  18X1" 

4Zs.  6X1" 
1  PI.  12  X  1" 

First  

12'  0" 

2  Pis.  16  Xf" 

4Zs.  6X1" 
1P1.  10X1" 

2  Pis.  18X}i" 

4Zs.  6X1" 
1P1.  12X1" 

Cellar.... 

12'  6" 

2  Pis.  16X13" 
4Zs.  6X1" 
1P1.  10X1" 

2  Pis.  18X11" 
4Zs.  6X1" 
1P1.  12X1" 

82       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  33 

1 
Col.  No.  34 

_J 

Col.  No.  35 

Col.  No.  36 

Twelfth.. 

4Ls.  2£X2Xi" 

4  Ls.  24X2X1" 

4  Zs.  3  X  \" 

1P1.  6iXi" 

IPL7XA" 

1  PI.  6  X  J" 

Eleventh 

10'  3" 

4Zs.  4Xi" 
1P1.  6iXi" 

- 

4  Zs.  5  X  iV 

4Zs.  6Xf" 

Tenth.  .  .  . 

10'  3" 

4Zs.6XiY' 

1  PI.  7  X  &" 

1P1..8XI" 

J 

Ninth.  .  .  . 

10'  3" 

1  PLSXiV 

J 

4  Zs.  6  X  i" 

4Zs.  6XU" 

Eighth.  .  . 

10'  3" 

4Zs.  6XH" 

[ 

1  PI.  8  X  i" 

J 

1  PI.  8XU" 
J 

Seventh.  . 

10'  3" 

g 

6 

1P1.  8X14" 

4Zs.  6Xli" 

4Zs.  6X1'2" 

Sixth.  .  .  . 

10'  3" 

pEj 

§ 

8 

2  Pis.  14XTV/ 
1  PI.  8X4" 
4Zs.  6X2" 

1P1.  8X11" 

J 

1P1.  8Xli" 
2  Pis.  14XiB0" 

Fifth  

10'  3" 

o> 

1P1.  8Xf" 

J  2PKJ4XA" 
4Zs.  6Xf" 

4Zs.  6X|" 

2  Pis.  14XTn" 
1-8X1" 
4Zs.  6X1" 

Fourth.  .  . 

10'  3" 

2  Pis.  14  X  A" 
1  PI.  8  Xi" 
4Zs.  6X|" 

1P1.  8Xi" 
2  Pis.  14XiV 

1  PI.  8X1" 

.   2  Pis.  14  XH" 

4Zs.  6X1" 

Third.... 

10'  3" 

I 

1  PL  8  XI" 

2  Pis.  14  XU" 
4  Zs.  6  Xi" 

2  Pis.  14X4" 
1-8X1" 
4Zs.  6XJ" 

2  Pis.  18X|" 
1-12X1" 
4Zs.  6X1" 

Second.  .  . 

10'  3" 

2  Pis.  18X1" 
4Zs.  6X1" 
1  PI.  12  Xi" 

1  PI.  8X1" 

2  Pis.  14  XI" 

4Zs.  6X1" 

1  PI.  12X1" 
4Zs.  6X1" 
J  2  Pis.  18X12" 

First  

12'  0" 

- 

2  Pis.  18  XU" 
4  Zs.  6  XV 
IP}.  12X1" 

2  Pis.  18X1" 
1  PI.  12X1" 
4Zs.  6X1" 

2  Pis.  20X1" 
1-14X1" 
4Zs.  6X1" 

Cellar.  .  .  . 

12'  6" 

2  Pis.  18X1" 
4Zs.  6X|" 
1-12X1" 

1P1.  12X1" 
2  Pis.  18X48" 
4Zs.  6X1" 

1  PI.  14X1" 
4  Zs.  6X1" 
2  Pis.  20XlTy 

WOOD  AND  METAL  FRAMING 


83 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  37 

Col.  No.  38 

Col.  No.  39 

Col.  No.  40 

Twelfth.. 

4Zs.  4X£" 

•i 

Eleventh 

10'  3" 

!PL6iXi" 

J 

Tenth.  .  .  . 

10'  3" 

4Zs.  6XiV 

Ninth.... 

10'  3" 

IPLSXiV 

Eighth.  .  . 

10'  3" 

4Zs.  6X1" 

Seventh.  . 

10'  3" 

1  PL  8X1" 

£ 
6 

•    . 

8 

6 

S 

Sixth.  .  .  . 

10'  3" 

j 

4  Zs.  6X1" 
2  Pis.  14XiV' 
1-8X1" 

fc 

3 
I 

K 

s 

1 

fc 

§ 

Fifth  

10'  3" 

2  Pis.  14  Xi" 

4Zs.  6X£" 
1  PI.  8Xi" 

o> 

a 

«3 
02 

02 

Fourth.  .  . 

10'  3" 

4  Zs.  6  Xi" 

1-8X1" 

2  Pis.  14  XH" 

Third.... 

10'  3" 

2  PI.  24  X  ,V' 
2  PI.  24  X  f" 
4  L.  6  X  4  X  I" 
2  PL  11  Xf" 
2P1.22X*" 

Second.  .  . 

10'  3" 

2  Pis.  24X,V 
2  PI.  24  X  i" 
4  L.  6X4X1" 
2  PI.  11  X|" 
2  PI.  22  Xi" 

First  

12'  0" 

2  PI.  24  X  f  " 
2  PI.  24  X  |" 
4  L.  6X4Xf" 
2  PI.  11  Xf" 
2  PI.  22  Xi" 

Cellar.  .  .  . 

|    12'  6" 

2  PI.  24  XF' 
2  PI.  24X5" 
4  L.  6X4X5" 
2  PI.  11  XT 
2  PI.  22X1" 

84       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  41 

Col.  No.  42 

'                                                      -Y» 

Col.  No.  43 

Col.  No.  44 

Twelfth. 

4  Zs.  4  X  A" 

4Zs.  3X1" 
1  PI.  6  X  J" 

4Ls.  2iX2Xi" 
1  PI.  eiXA" 

Eleventh 

10'  3" 

1P1.6JXA" 

4Zs.  5X1" 

*- 

4Zs.  4XA" 

Tenth.  .  .  . 

10'  3" 

4  Zs.  6X&" 

1  PI.  7X|" 

1P1.  6*X,y' 

Ninth.... 

10'  3" 

1  PI.  8XiV 

4  Zs.  6XiV' 

4  Zs.  6X,V 

Eighth.  .  . 

10'  3" 

4Zs.  6XU" 

1  PI.  SXiV 

IPl.SXiV 

Seventh.  . 

10'  3" 

1  PI.  8XB" 

4  Zs.  6X|" 

^ 
6 

4  Zs.  6XH" 

Sixth  

10'  3" 

4  Zs.  6Xli" 

1  PI.  8X1" 

£; 

s 

I 

1  1P1.8X1J" 

Fifth  

10'  3" 

1  PI.  8Xli" 
2  Pis.  14  Xi" 

4  Zs.  6X}i" 

1 

4  Zs.  8X}r 

Fourth.  .  . 

10'  3" 

2  Pis.  14X1" 
1  PI.  6  XI" 
4  Zs.  6X1" 

1  PI.  8XH" 

1  PI.  6X11" 
2  Pis  .14XiV 

Third.  .  .  . 

10'  3" 

1  PL  8X1" 

2  Pis.  14  Xf" 
4Zs.  6X1" 

4Zs.  6X1" 

2  Pis.  14X1" 
1-8X11" 

4Zs.  6Xlf' 

Second.  .  . 

10'  3" 

2  Pis.  18  X  V 
1-12X1" 
4  Zs.  6X1" 

1  PI.  8X1" 
2  Pis.  14  X  A" 

1  PI.  8X!i" 
4Zs.  6X11" 

2  Pis.  14  Xf" 

First  

12'  0" 

1  PI.  12X1" 

2  Pis.  18X1J" 
4Zs.  6X1" 

2  Pis.  14  X  A" 
1  PI.  8X1" 
4Zs.  6X1" 

1-6X1" 

2  Pis.  14  XH" 
4  Zs.  6X1" 

Cellar.... 

12'  6" 

1  PI.  12X1" 
2  Pis.  18X1" 
4Zs.  6X1" 

1  PI.  8X1" 
2  Pis.  14  Xf" 
4Zs.  6X1" 

1  PL  8X1" 
4  Zs.  6  XI" 
2  Pis.  14X1" 

WOOD  AND  METAL  FRAMING 


85 


SCHEDULE  OF  COLUMNS — Continued 


Floor 

Height 
between 
floors 

Col.  No.  45 

Col.  No.  46 

Col.  No.  47 

Col.  No.  48 

Twelfth 

4  Ls  2iX2Xj" 

1  PI.  6  X  1" 

4  Zs.  4  X  i" 

Eleventh: 

10'  3" 

4  Zs.  3  X  i" 
1  PI.  6  X  1" 

1  PL  6iXl" 

Tenth.... 

10'  3" 

4  Zs.  5X1" 

4  Zs.  5  X  &" 

Ninth.  .  .  . 

10'  3" 

1  PI.  7Xf" 

1  PL  7X&" 

Eighth.  .  . 

10'  3s" 

4Zs.  6X&" 

4  Zs.  6  X  J8" 

Seventh.  . 

10'  3" 

1  PI.  8X&" 

3 

6 

1  PL  8XM" 

Tt< 

CO 

6 

Sixth  

10'  3" 

4Zs.  6X11" 

!<c 

§ 

a 

1      2-14XS" 
1      1-8X1" 
4Zs.  6Xf" 

% 

3 
§ 

Fifth  

10'  3" 

1  PL  8X}i" 

o 

.  1  PL  8  X  f  " 

2  Pis.  14  XU" 
4Zs.  6X|" 

m 

Fourth.  .  . 

10'  3" 

2  Pis.  14Xis«" 
1-8XH" 
4Zs.  6XH" 

}    2Pls.  16  Xi" 
10X1" 
4  Zs.  6X1" 

Third.... 

10'  3" 

1  PL  8Xii" 

2  Pis.  14X1" 
4  Zs.  6X13" 

1  PL  10X1" 

2  Pis.  16X1" 
4Zs.  6X1" 

Second..  . 

10'  3" 

1  PL  8X|" 

2  Pis.  14  Xi" 
4Zs.  6X1" 

1  PL  14X1" 

2  Pis.  20  X?" 
4  Zs.  6X1" 

First  

12'  0" 

1  PL  8X1" 
4Zs.  6  Xf" 
2  Pis.  14XH" 

1  PL  14X1" 

2  Pis.  20X1S" 
4  Zs.  6X1" 

Cellar.  .  .  . 

12'  6" 

2  Pis.  14X1" 
1-8X1" 
4  Zs.  6  XI" 

1  PL  14X1" 
2  Pis.  20  XU" 
4Zs.  6X1" 

86       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  49 

V 

Col.  No.  50 

Col.  No.  51 

Col.  No.  52 

Twelfth.. 

'   •               f" 
4  Zs.  4XA" 

4Ls.  2*X2X1 
1  PI.  6XJ" 

Eleventh 

10'  3" 

1  PI.  ejXaV 

4  Zs.  3  X  !"*• 
1  PI.  6  X  i" 

Tenth.  .  .  . 

10'  3" 

4  Zs.  6XiV 

4Zs.  5X1" 

Ninth.  .  .  . 

10'  3" 

1  PI.  8  X  ft" 

1  PI.  7Xf" 

Eighth.  .  . 

10'  3" 

4  Zs.  6X1" 

4  Zs.  6Xi" 

Seventh.  . 

10'  3" 

t* 

•<*< 

6 

1  PI.  8X1" 
J 

1  PI.  8Xi" 

8 

6 

Sixth.  .  .  . 

10'  3" 

fc 

3 
i 

}  2  Pis.  14X1" 
1-8X1" 
4  Zs.  6X1" 

} 

4Zs.  6Xf" 

i 

K 

§ 

Fifth  

10/  3"                   1 

1  PI.  8X1" 

J  2  Pis.  14  Xf" 

4Zs.  6X1" 

1     1P1.  8Xi" 

! 

a 

Fourth.  .  . 

10'  3" 

2  Pis.  18X1" 
1-12X1" 
4  Zs.  6X1" 

4Zs.  6X1?" 

Third  

10'  3" 

1  PI.  12X1" 
2  Pis.  18X1" 

4Zs.  6X1" 

1  PI.  8X}g" 
2  Pis.  14Xf" 

Second.  .  . 

10'  3" 

1  PI.  14X1" 

2  Pis.  20  X  li" 
4Zs.  6X1" 

1  PL  8Xii" 

2  Pis.  14  Xf" 
4  Zs.  6  X  12" 

First  

12'  0" 

2Pls.20XlrV 
1-14X1" 
4  Zs.  6X1" 

2  Pis.  14X^8" 
l-SXii" 
4Zs.  6X18" 

Cellar.  .  .  . 

12'  6" 

2  Pis.  20Xlf"     2  Pis.  14X13" 
1-14X1"            4  Zs.  6X13" 
4Zs.  6X1               1-18X1S" 

WOOD  AND  METAL  FRAMING 


87 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  53 

Col.  No.  54 

Col.  No.  55 

Col.  No.  56 

Twelfth 

4Ls.  2£X2Xi" 

4  Ls  2^X2X1" 

4  Ls  2iX2Xl" 

1  PI.  6iX|" 

1  P1.6Xi" 

Eleventh. 

10'  3" 

4  Zs.  3Xi" 
1  PL  6XJ" 

4Zs.  4Xf" 

4  Zs.  3  X  \" 

ipi.exi" 

Tenth.  .  .  . 

10'  3" 

4  Zs.  6X1" 

1  PL  6iXf" 

J 

4Zs.  5Xft" 

Ninth.  .  .  . 

10'  3" 

1  PL  8X1" 

4  Zs.  6XiV 

1P1.  7XA" 

J 

Eighth.  .  . 

10'  3" 

4  Zs.  6  X  f  " 

1  PL  8  X  ft" 

J 

4  Zs.  5Xi" 

Seventh.  . 

10'  3" 

1  PL  8  X  I" 

j 

4  Zs.  6X12" 

6 

1  PL  7Xi" 
J 

Sixth  

10'  3" 

4Zs.  6X1" 

1  PL  8Xli" 

J 

3 

4Zs.  5XH" 

Fifth  

10'  3" 

1  PL  8X1" 

2  Pis.  14  Xf" 
1-8X1" 
4  Zs.  6Xf" 

i 

0) 

1  PL  7XH" 

Fourth.  .  . 

10'  3" 

2  Pis.  14XtV 
1-8X1" 
4  Zs.  6X1" 

I    1  PL  8X2" 

J  2  Pis.  14  Xf" 
4  Zs.  6X1" 

4Zs.  6Xf" 

Third.... 

10'  3" 

1  PL  8X1" 

2  Pis.  14  Xf" 
4Zs.  6X1" 

2  Pis,  14X|" 
1-8X1" 
4  Zs.  6X1" 

1  PL  8  X  \" 

J 

Second..  . 

10'  3" 

}  2  Pis.  14Xft" 
1-8X1" 
4  Zs.  6"  XI 

1  PL  8X1" 

2  Pis.  14X1" 
4  Zs.  6  XI" 

2  Pis.  14  X  ft" 
l-8Xi 
4Zs.  6Xf" 

First  

12'  0" 

1  PL  8X1" 

2  Pis.  14Xtr' 
4  Zs.  6  XI" 

2  Pis.  18  XS" 
1-12X1" 
4  Zs.  6X1" 

1  PL  8XJ" 

2  Pis.  14  Xf" 
4Zs.  6Xi" 

Cellar.... 

12'  6" 

4  Zs.  6X1" 
1  PL  10X1" 
2  Pis.  16Xia" 

1  PL  12X1" 
2  Pis.  ISXii" 
4  Zs.  6  XI" 

1  PL  6  X  1" 
2  Pis.  14Xft" 
4  Zs.  6  X| 

88       ENGINEERING  OF  SHOPS  AND  FACTORIES 


SCHEDULE  OF  COLUMNS— Continued 


Floor 

Height 
between 
floors 

Col.  No.  57 

Col.  No.  58 

Col.  No.  59 

Twelfth 

4  Ls  2*X2Xl" 

•'.  , 

4  Ls  2*X2X1" 

1  PI.  6  X  J" 

1P1.  7X1" 

Eleventh 

10'  3" 

4  Zs.  3  X  1" 
1  PI.  6  X  1" 

4Zs.  5X|" 

». 

Tenth.... 

10'  3" 

4Zs.  5X1" 

1  PI.  7X1" 

Ninth  

10'  3" 

1  PI.  7X|" 

4Zs.  6X1" 

Eighth.  .  . 

10'  3" 

4Zs.  6XrV 

IPLSXf" 

Seventh.  . 

10'  3" 

1P1.  8XiV 

»o 
•^ 

6 

4Zs.  6X1" 

Sixth  

10'  3" 

4Zs.  6Xf" 

^ 

§ 

a 

1  PI.  8X1" 

Fifth  

10'  3" 

1  PI.  8  X  f  " 

® 

]  2  Pis.  14X/a" 
1-8XH" 
4  Zs.  6  X  B" 

Fourth.  .  . 

10'  3" 

4Zs.  6X1" 

1P1.  8Xii" 

2  Pis.  14  X  A" 
4  Zs.  6X}§" 

Third.... 

10'  3" 

1  PI.  8X1" 
2  Pis.  14  X  &". 

Second.  .  . 

10'  3" 

2  Pis.  14  Xt" 
4Zs.  6X1" 
1  PI.  8X1" 

First  

12'  0" 

2  Pis.  14X4" 
4Zs.  6X1" 
1  PI.  8X1" 

Cellar.  .  .  . 

12'  6" 

2  Pis.  14  XH" 
4Zs.  6X1" 
1  PI.  8X1" 

4Zs.  3X1" 
1  PI.  6  X  1" 

WOOD  AND  METAL  FRAMING 


89 


being  placed  just  above  one  floor  and  ^the  remaining  ones  above 
the  floors  adjoining. 
Framing  of  Domes. — A  dome  is  sometimes    anf  appropriate 


FIG.  50. — Market  building  with  dome. 

feature  for  the  office  or  executive  building  of  an  industrial  plant, 
distinguishing  it  plainly  from  the  surrounding  shops,  and  it  is 
frequently  used  on  markets1  and  exhibition  halls.  Fig.  50.  The 


ilL 


[\=L1 

1 1    I  i; 


FIG.  51. — Office  building  with  dome. 

dome  affords  not  only  a  beautiful  feature  in  itself  by  day,  but 
gives  opportunity  for  electric  illumination  by  night,  and  it  can 
be  made  an  effective  means  of  advertising,  as  the  lights  at  a  con- 
1  H.  G.  Tyrrell,  in  Architect's  and  Builders'.  Magazinef.J\ily,  1901. 


90       ENGINEERING  OF  SHOPS  AND  FACTORIES 


FIG.  52. — Office  building  with  dome.     Framing  plan. 


WOOD  AND  METAL  FRAMING  91 

siderable  elevation  are  conspicuous.  No  form  of  roof  lends 
itelf  with  greater  effect  to  the  art  of  the  electrician,  for  the  lines 
both  inside  and  out  are  so  easily  traced  with  rows  of  lights  that  the 
effect  at  night  is  beautiful.  No  one  who  has  visited  any  of  the 
recent  World's  Fairs,  and  has  taken  time  to  study  and  admire  the 
illumination,  can  fail  to  appreciate  this  form  of  construction.  All 
the  principal  lines  are  indicated  with  lamps,  the  numerous  ridges 
radiating  from  the  center  to  the  base — the  base  itself — and  the 
crown,  are  all  brought  out  in  curves  of  light.  And  inside  of  the 
building,  the  effect  may  be  even  more  attractive.  A  circle  of 
globes  surrounds  the  inner  lining  of  the  dome,  and  each  rib 
radiating  from  the  center  is  studded  with  gems,  while  at  the  center 
is  a  brilliant  cluster. 

Since  beauty  and  utility  are  now  so  often  combined  in  the  design 
of  factory  buildings,  an  illustration  is  given  for  the  framing  of  a 
dome  which  is  suitable  for  an  office,  or  such  other  buildings  as  a 
library  or  welfare  hall,  which  are  now  so  often  a  part  of  large  works. 

The  roof  herewith  described  (Figs.  51  and  52)  is  78  ft.  wide,  97 
ft.  long  and  the  dome  is  37  ft.  in  outside  width.  It  is  covered  on 
the  outside  with  curved  sheets  of  rough  wire  glass  supported  on 
copper  ribs,  and  is  lined  on  the  inside  with  another  dome  of  colored 
glass  supported  on  a  light  frame  suspended  from  the  main  ribs. 

An  unusual  feature  of  the  framing  is,  that  no  bending  is 
required  excepting  for  the  copper  skylight  ribs.  The  dome  is 
octagonal  in  form  and  each  of  the  trusses  is  made  of  straight 
sections.  These  trusses  carry  the  purlins,  which  in  turn  support 
the  skylight.  To  resist  the  bursting  effect  at  the  base  of  the 
dome,  as  well  as  to  carry  its  own  weight  an  arrangement  of  beams 
and  trusses  is  provided  connecting  with  the  roof  principals,  and 
thence  to  the  wall  columns.  The  bursting  tendency  produces  a 
tension  of  3000  Ibs.  in  the  members  encircling  the  base  of  the  dome. 
Each  of  the  main  ribs  intersects  at  an  angle  of  the  supporting 
octagon,  thus  insuring  only  direct  tension  in  the  outside  members. 

The  main  roof  is  covered  with  slate  on  7/8  in.  boards  laid  on 
tiles  between  7-in.  steel  purlin  beams.  The  ceiling  also  is  made 
of  tile  between  6-in.  beams,  and  the  whole  is  furred  and  plastered 
on  the  under  side  from  the  wall  to  the  opening  of  the  dome.  On 
all  four  sides  of  the  main  room  is  a  heavy  cornice  of  expanded 
metal  and  plaster,  and  the  whole  interior,  both  ceiling  and  dome, 
are  brilliantly  lighted  with  electric  lamps.  The  coloring  of  the 
interior  dome  produces  a  beautiful  effect  by  day,  and  the  re- 


92       ENGINEERING  OF  SHOPS  AND  FACTORIES 

flection  of  these  colors  through  the  outer  dome  presents  even  a 
more  beautiful  exterior  effect  at  night. 

The  weight  of  steel  in  the  roof  and  columns,  is  as  follows: 

Eight  columns 27,600  Ib. 

Ceiling 17,600  Ib. 

Trusses  and  purlins. . . 101,100  Ib. 


146,300  Ib. 

The  total  cost  of  the  steel  work  is  $4300,  which  is  equal  to  55 
cents  per  square  foot  of  ground  covered. 

Trusses  and  columns  are  placed  at  the  rear  gable  and  at  the 
interior  partition,  with  a  view  to  a  possible  removal  of  the 
partition  wall,  or  extension  on  the  rear  end.  If  such  changes  are 
not  anticipated,  two  trusses  and  four  columns  could  be  omitted, 
and  the  weight  of  steel  reduced  to  115,300  Ib.  and  the  cost  to 
$3600.  This  is  equal  to  14  1/2  Ib.  or  45  cents  per  square  foot  of 
ground  covered. 

The  tile  roof  and  ceiling  is  fireproof,  but  quite  heavy  and 
expensive.  If  it  were  essential  to  reduce  the  cost  still  further, 
a  cheaper  covering  such  as  slate  on  plank  could  be  used,  which 
would  not  only  cost  less  in  itself,  but  since  it  is  lighter,  would  re- 
duce the  weight  of  the  steel  framing. 

If  the  skylight  is  not  required,  the  dome  might  be  covered 
with  metal  instead  of  glass,  and  the  interior  or  lining  made  of 
plaster.  The  domes  of  monumental  buildings  are  usually  gilded 
on  the  exterior,  which  makes  them  conspicuous  during  day-light, 
but  if  this  expense  is  not  desired,  they  may  be  covered  with  plain 
bright  metal  which  is  easily  seen  at  a  great  distance.  In  either 
case,  electric  illumination  may  be  used  at  night.  Ventilation 
must  be  provided,  especially  with  glass  covering;  otherwise  the 
excessive  summer  heat  is  liable  to  crack  or  melt  the  glass.  An 
ornamental  ventilator  is  shown  on  the  drawing,  but  if  preferred, 
the  dome  may  be  finished  with  a  simple  crown,  and  ventilation 
provided  through  port  holes  in  the  side  or  louvres  around  the  base. 

The  cost  of  the  roof  with  dome  is  about  $700  more  than  if 
roofed  directly  over,  and  an  equal  amount  of  light  admitted 
through  several  box  skylights.1 

Long  Span  Roofs. — Although  long  roof  spans  without  inter- 
mediate columns  are  not  often  used  for  shops  and  factories, 
they  are  frequently  convenient  for  such  buildings  as  rolling  mills, 

1  H.  G.  Tyrrell,  in  Architects'  and  Builders?  Magazine,  March,  1905. 


WOOD  AND  METAL  FRAMING 


93 


and  are  usually  preferred  for  drill  halls,  armories,  exhibition 
halls,  train  sheds,  etc.,  (Fig.  53).  As  the  floor  is  then  free  from 
columns,  tracks  or  machinery  can  be  placed  anywhere  without 
restriction.  Wide  spans  are,  however,  not  economical  when 
hoisting  appliances  are  suspended  from  the  framing,  for  the 
weight  and  cost  of  trusses  increases  rapidly  with  the  span  and 
supported  load. 

For  the  purpose  of  estimating  approximately  the  weight  and 
cost  of  long  span  roofs,  without  inside  columns,  the  following 
data  will  be  useful.  The  weights  are  for  the  steel  only,  including 
trusses,  shoes,  bracing  and  purlins,  but  they  do  not  include  wooden 
jack  rafters,  boards  or  covering,  nor  any  gallery  framing. 
Weights  given  are  per  square  foot  of  sloping  roof  surface.  Arched 


FIG.  53. — Roof  without  interior  columns. 

roofs,  not  including  the  items  mentioned  above,  usually  weigh 
from  8  to  12  Ib.  per  square  foot  of  outside  area.  All  of  the 
following  cases  were  proportioned  for  slate  and  plank  roofing  on 
wood  rafters  2  ft.  apart,  supported  by  steel  purlins  at  intervals  of 
about  10  ft.  The  unit  stresses  were  12,000  and  15,000  Ib.  per 
square  inch  in  compression  and  tension  respectively.  They  all 
have  curved  arch  ribs  and  are  similar  in  general  outline.  The 
spans  are  the  distances  between  centers  of  side  bearings,  which 
are  4  to  5  ft.  less  than  the  outside  width  of  the  building.1 

The  assumed  loads  on  these  roofs  are  as  follows: 
Dead  weight  of  roof  and  covering,  for  trusses,  25  Ib.  per  square 
foot  of  sloping  surface,  and  for  purlins,  18  Ib.  per  square 
foot. 

1  H.  G.  Tyrrell,  in  Architect's  and  Builders'  Magazine,  Oct.,  1901. 


94       ENGINEERING  OF  SHOPS  AND  FACTORIES 

Dead  weight  of  snow,  10  Ib.  per  square  foot  of  sloping  surface 
Wind  pressure  was  assumed  at  40  Ib.  per  square  foot  horizontal 

or  28  Ib.  normal  to  the  surface. 

Pawtucket  armory  is  82  ft.  wide  and  143  ft.  long,  with  five 
main  trusses,  24  ft.  apart.  The  roof  pitch  is  33  degrees,  and  the 
heights  are,  16  ft.  to  eave,  and  40  ft.  to  ridge. 

jm 

QUANTITIES 

5  trusses 67,000  Ib. 

42  purlins 28,000  Ib. 

12  purlins 7,500  Ib. 

bracing 6,100  Ib. 

5  ties 2,900  Ib. 

10  shoes 4,500  Ib. 


Total 116,000  Ib. 

This  weight  is  equivalent  to  8.7  Ib.  per  square  foot  of  sloping  roof 
surface. 

Portland  armory  has  a  span  of  92  ft.,  and  length  of  153  ft., 
with  five  main  trusses  25  ft.  apart.  Its  height  to  eaves  is  24  ft., 
and  to  the  ridge  50  ft. 

QUANTITIES 

3  trusses  at  17,860  Ib 53,580  Ib. 

2  trusses  at  19,700  Ib 39,400  Ib. 

6  cast  shoes 2,100  Ib. 

4  cast  shoes 1,400  Ib. 

3  tie  rods 2,457  Ib. 

2  tie  rods 1,980  Ib. 

28  purlins 19,100  Ib. 

8  purlins 9,600  Ib. 

18  purlins 22,400  Ib. 

8  purlins 5,184  Ib. 

4  purlins 2,876  Ib. 

44  bracing  struts 4,488  Ib. 

.       36  bracing  struts 3,300  Ib. 

72  rods 3,540  Ib. 


Total 171,400  Ib. 

This  weight  corresponds  to  9.7  Ib.  per  square  foot  of  sloping  roof 
surface,  or  11.7  Ib.  per  square  foot  of  ground  covered.     The 
trusses  in  this  case  were  made  strong  enough  to  carry  a  13-ft. 
gallery  on  two  sides  and  one  end,  to  be  added  in  the  future. 
Phoenix  Hall  (Fig.  54),  Brockton,  Mass,  is  100  ft.  wide,  and 


WOOD  AND  METAL  FRAMING 


95 


144  ft.  long  outside.  It  has  five  main  arches  94  ft.  center  to 
center.  Distance  between  trusses  is  24  ft.  It  is  33  ft.  high  to 
eaves,  and  67  ft.  to  the  ridge,  and  has  a  gallery  17  ft.  wide. 
The  only  steel  included  for  the  gallery  is  that  for  the  ten 
brackets. 


FIG.  54. — Three-hinged  arch  roof. 


QUANTITIES 

42  purlins. 28,700  Ib. 

48  struts 6,600  Ib. 

rod  bracing 2,600  Ib. 

5  tie  rods 4,680  Ib. 

5  arches t 99,500  Ib. 

10  shoes ' 3,100  Ib. 

10  gallery  brackets 6,060  Ib. 


Total 151,240  Ib. 

This  weight  is  equal  to  8.6  Ib.  per  square  foot  of  sloping  roof  sur- 
face, or  10.6  Ib.  per  square  foot  of  ground  covered. 

Northampton  Armory,  is  100  ft.  wide  and  long,  or  square  in 
plan.  It  has  three  main  trusses,  and  eleven  lines  of  trussed 
purlins,  and  no  gallery. 


96       ENGINEERING  OF  SHOPS  AND  FACTORIES 

QUANTITIES 

3  trusses  at  17,000  Ib 51,000  Ib. 

6  cast  shoes  at  350  Ib 2,100  Ib. 

3  tie  rods  at  780  Ib 2,340  Ib. 

44  purlins  at  670  Ib 29,500  Ib. 

bottom  chord  struts 5,200  Ib. 

bottom  chord  ties. .'. /* 2,100  Ib. 


Total 92,240  Ib. 

fc 
As  the  sloping  roof  area  is  11,600  sq.  ft.  the  weight  per  square 

foot  is  7.95  Ib. 

Hartford  Rink  is  104  ft.  wide,  and  124  ft.  long.  It  has  four 
main  ribs  54  ft.  high  center  to  center  of  pins,  is  24  ft.  high  to 
eaves,  and  has  a  gallery  16  ft.  above  the  floor,  which  in  this  case 
is  framed  of  steel,  the  main  brackets  being  framed  with  the 
trusses.  The  roof  has  seven  lines  of  trussed  purlins. 

QUANTITIES 

Trusses  and  rafters 132,400  Ib. 

Purlins 34,400  Ib. 

Rods 18,000  Ib. 


Total 184,800  Ib. 

Gallery 67,600  Ib. 

The  total  exposed  roof  area  is  15,600  sq.  ft.,  and  the  weight  per 
square  foot  is  therefore: 

Roof 184,800-^15,600  =  11.8  Ib. 

Gallery 67,000^-15,600  =   4.4  Ib. 

Providence  Exposition  Hall. — This  is  118ft.  wide,  and  196  ft. 
long,  and  has  seven  main  trusses,  20  ft.  high  to  eaves. 

QUANTITIES 

7  trusses  at  25,000  Ib 175,000  Ib. 

105  purlins  at  580  Ib 60,300  Ib. 

7  tie  rods  at  1,100  Ib 7,700  Ib. 

Rafter  bracing 4,000  Ib. 

96  struts  at  100  Ib 9,600  Ib. 

14  cast  shoes  at  600  Ib 8,400  Ib. 

Total..                                                265,000  Ib. 


WOOD  AND  METAL  FRAMING 


97 


This  weight  corresponds  with  9.5  Ib.  per  square  foot  sloping,  or 
11.5  Ib.  per  square  foot  horizontal. 

The  following  table  gives  a  summary  of  weights  and  data  for 
the  roofs  described  above. 


TABLE  OF  LONG  SPAN  ROOFS 


Weight 

Weight 

Span 
ft 

Length 
ft 

Truss 
spacing 

Height 
to  eave, 

Gallery 

per  square 
foot, 

per  square 
foot 

One 
truss, 

ft. 

ft. 

sloping, 

horizontal, 

Ib. 

Ib. 

Ib. 

Pawtucket  

82 

143 

24 

16 

None 

8.7 

10 

13,400 

Portland 

92 

153 

25 

24 

9  7 

11  7 

18  000 

Phoenix  

96 

144 

24 

33 

8.6 

10.6 

20,000 

Northampton.. 

100 

100 

24 

None 

8.0 

9.2 

17,000 

Palace  

104 

124 

25 

24 

11.8 

14.7 

23,000 

Providence.  .  .  . 

118 

196 

24.5 

20 

None 

9.5 

11.5 

25,000 

Cleveland 

120 

23 

Boston  

122 

300 

30 

16.5 

None 

12.4 

16.2 

42,000 

New  York.. 

176 

225 

24.5 

Brooklyn 

196 

300 

35 

32 

10 

All  of  the  above  examples  have  arch  action,  a  graphical  analysis 
of  stresses  for  a  typical  case  being  shown  in  Fig.  55.  A  simple 
truss  roof  with  curved  lower  chord  but  without  any  arch  action 
is  illustrated  in  Fig.  56. 

For  the  purpose  of  comparison,  the  following  table  is  given  of 
long  roof  spans  for  train  sheds: 


TRAIN  SHED  ROOFS 


Place 

Railroad  Co. 

Span 
ft 

Length 

ft 

Rise 

ft 

Number 
of 

Area 
Covered 

Tracks 

sq.  ft. 

Jersey  City  

C.  R.  of  N.  J  

142 

512 

12 

New  York 

Grand  Central 

199 

652 

94 

129  800 

Chicago  

C.  R.  I.  &  P  

207 

578 

11 

London 

Midland 

240 

706 

107 

169  400 

Jersey  City  

P.  R.  R  

252 

653 

90 

12 

164,900 

Pittsburg 

P    R    R        

255 

555 

12 

Philadelphia  

P.  &  R  

259 

506 

88 

13 

131,200 

Philadelphia  

P.  R.  R  

300 

598 

108 

16 

177,100 

98       ENGINEERING  OF  SHOPS  AND  FACTORIES 


Cost  of  Steel  Frame  Buildings. — One-story  steel  mill  buildings 
erected  complete,  with  solid  walls  and  crane  supports,  cost  80 
cents  to  $1.10  per  square  foot  of  ground  covered, 
not  including  ground  floors  or  foundations,  and 
similar  buildings  with  crane  supports  and  corrugated 
iron  walls  will  cost  from  70  cents  to  $1  per 
square  foot.  One-story  steel  frame ''sheds 
or  buildings  (Fig.  57)  without  provision 
for  cranes,  and  with  corrugated 
iron  covering,  will  cost,  erected 
complete,  from  50  to  70  cents 
per  square  foot  of 
ground  covered. 

The  cost  of  mate- 
rials, at  the 
place    of 
manufac- 


-74 -6" Span 
FIG.  55. — Three-hinged  arch  roof.     Stress  sheet. 

ture  but  not  erected,  for  steel  frame  buildings  with  sheet  metal 
covering,  including  structural  steel,  corrugated  iron,  doors,  win- 
dows, flashings,  gutters,  conductors,  but  without  ground  floor  or 
foundations,  is  as  follows:  Machine  shops  and  foundries,  40  to 
50  cents  per  square  foot  of  ground  covered;  sheds,  enclosed  on 
roof  and  sides,  30  to  40  cents  per  square  foot  of  ground  covered. 


WOOD  AND  METAL  FRAMING 


99 


The  cost  of  corrugated  iron  buildings  (Fig.  58)  without  cranes 
may  also  be  approximated  by  finding  the  total  exposed  outside 


Diaqram-Futl  Loads 

,  k^  i ' 

+&£ 


Diaqram  -Wind  and  Ceilinq 
One  Side  only 


FIG.   56. — Sample  roof  truss  with   curved  bottom  chord.     Stress  sheet. 


area  of  the  building,  including  both  walls  and  roof,  and  multi- 
plying it  by  30  cents  per  square  foot.     Steel  frames  for  cranes 


100     ENGINEERING  OF  SHOPS  AND  FACTORIES 


including  supports  and  girders  only,  cost  from  70  cents  to  $1  per 
lineal  foot  of  building  for  every  ton  capacity  of  the  crane. 

The  weight  of  steel  frames  in  multi-story  factory  buildings 


FIG.  57. — Metal  covered  boiler  house. 

not  over  eleven  stories  in  height,  with  steel  joist,  girders  and 
columns,  designed  according  to  modern  specifications  and 
building  laws,  with  columns  15  to  16  ft.  apart  are  as  follows: 


FIG.  58. — A  power  house. 

TABLE  V.— WEIGHT  OF  STEEL  FRAMES  IN  MULTI-STORY  BUILDINGS 


Imposed  floor  load, 
pounds  per  squar  efoot 

Exterior  walls 

Weight  of  steel,  pounds 
per  square  foot  of  floor 

60 

With  outside  frame. 

14 

60 

Without  outside  frame. 

9 

100 

With  outside  frame. 

23 

100 

Without  outside  frame. 

15 

250-300 

With  outside  frame. 

28 

250-300 

Without  outside  frame. 

18 

H.  G.  Tyrrell,  in  Architects'  and  Builders'  Magazine,  Jan.,  1903. 


WOOD  AND  METAL  FRAMING 

The  approximate  cost  of  the  steel  frame  for  a  building  of 
several  stories  can  readily  be  obtained  by  multiplying  any  of  the 
above  weights  per  square  foot,  by  the  total  floor  area  and  the 
cost  of  steel  per  pound,  which  is  usually  from  2i  to  3^  cents 
erected. 
Fireproof  steel  buildings  in  cities,  with  terra  cotta  floor  arches, 

cost,  when  complete,  20  to  25  cents  per  cubic  foot. 
Fireproof  steel  buildings  in  cities,  with  concrete  floors,  cost  from 

15  to  18  cents  per  cubic  foot. 
The  finished  cost  of  those  with  terra  cotta  floors  is  usually  from 

$2  to  $3  per  square  foot  of  floor. 

Estimates  on  building  work  for  export  to  other  countries  are 
usually  made  for  the  materials  delivered  on  the  wharf  at  some 
seacoast  city,  from  which  ships  sail  for  the  foreign  port.  These 
estimates  include  American  prices  only,  and  foreign  ones  need  be 
considered  only  when  the  American  firm  intends  to  complete 
the  building  in  the  foreign  country. 


CHAPTER  VIII 
CONCRETE  FRAMING  K 

It  is  well  known  that  concrete  was  extensively  used  by  the 
Romans  2000  years  ago  or  more,  as  the  dome  of  the  Pantheon 
and  many  other  Roman  buildings  are  of  this  material.  Concrete 
reinforced  with  metal  was  more  or  less  used  through  succeeding 
ages,  for  walls  of  this  material  faced  with  stone,  were  lately  dis- 
covered when  putting  in  new  lifts  in  the  Louvre  at  Paris,  which 
was  built  by  order  of  Francis  I  in  the  sixteenth  century.  The 
material  itself  is  therefore  very  old,  the  only  new  feature  being  its 
commercial  use  and  application. 

The  modern  high-grade  product  known  as  Portland  cement  was 
discovered  by  Joseph  Aspdin  of  Leeds,  England  in  1824,  and  it  is 
to  the  recent  development  of  methods  for  producing  it  in  large 
quantities  at  low  cost,  that  much  of  the  recent  progress  is  due. 
The  first  reinforced  concrete  building  in  the  United  States  was 
a  residence  at  Port  Chester,  N.  Y.  erected  in  1875,  and  three  years 
later  the  first  really  important  American  patent  in  this  material 
was  issued  to  Thaddeus  Hyatt,  though  other  ones  of  less  practical 
value  had  been  granted  as  early  as  1844.  The  first  reinforced 
concrete  factory  in  America  was  erected  in  1887-1888  by  Mr. 
Ernest  L.  Ransome,  but  the  type  seems  to  have  met  with  no 
great  favor,  as  the  second  one  of  the  kind  was  not  undertaken 
for  another  ten  years,  when  Mr.  Ransome  erected  one  for  The 
Pacific  Coast  Borax  Company  at  Bayonne,  N.  J.  The  early 
efforts  of  this  American  pioneer  in  concrete  building  seem  to 
have  been  discouraging,  for  the  new  system  received  no  general 
recognition  until  about  1902  when  several  buildings  of  the  type 
appeared.  During  the  next  five  years  about  forty  shops  and 
factories  in  reinforced  concrete  were  built  in  America,  and  since 
that  time  the  number  is  too  great  to  enumerate.  Progress 
is  well  illustrated  by  a  table  showing  the  amount  of  cement 
produced. 

102 


CONCRETE  FRAMING  103 

TABLE  VI.— CEMENT  PRODUCTION  OF  THE  UNITED  STATES  (IN  BARRELS) 

I 

Portland  Natural 


1890 

300,000 

1896 

1,000,000 

1899 

5,652,000 

9,868,000 

1900 

8,500,000 

1901 

12,711,000 

7,085,000 

1903 

22,325,000 

7,030,000 

1905 

35,247,000 

4,473,000 

1906 

46,400,000 

1907 

48,785,000 

2,887,000 

1909 

64,991,000 

1,538,000 

1910 

76,550,000 

1,139,000 

The  1910  production  of  76,550,000  barrels  of  Portland  cement 
had  a  weight  of  13,000,000  tons,  and  at  $5.25  per  ton,  was 
valued  at  $68,205,000.  This  yearly  product  was  18  per  cent, 
greater  than  during  the  preceding  year,  the  average  cost  in  the 
United  States  being  89  cents  per  barrel.  The  whole  world 
production  of  Portland  cement  in  1910  was  130,000,000  barrels, 
or  less  than  twice  as  much  as  that  of  the  United  States.  It 
appears  from  the  above  table  that,  as  the  production  of  Portland 
cement  has  steadily  increased,  the  use  of  natural  cement  has 
decreased.  There  seems  to  have  been  a  decrease  also  in  struc- 
tural steel,  for  while  the  production  of  one  European  country 
in  1906  was  1,200,000  tons,  it  decreased  in  1908  and  1909  to 
830,000  and  1,045,000  tons  respectively. 

Advantages  of  Concrete  Construction. — Plain  concrete  without 
reinforcing  is  strong  in  compression  and  is  therefore  well  suited 
for  heavy  structures  with  only  compressive  stress,  such  as  walls, 
piers,  abutments,  foundations,  short  columns  etc.,  as  ordinary 
mixtures  of  concrete  are  at  least  three  times  as  strong  as  the 
best  quality  of  brick  work. 

Some  of  the  advantages  of  reinforced  concrete  buildings  are 
as  follows: 

1.  They  are  monolithic,  with  the  solidity  of  stone,  and  grow 
harder  with  age.  Floors  may  after  a  few  years  sustain  loads 
50  to  100  per  cent,  greater  than  those  for  which  they  were 
originally  designed,  or  additional  stories  can  be  added  without 
strengthening  the  original  frame. 


104     ENGINEERING  OF  SHOPS  AND  FACTORIES 

2.  They  are  fireproof  and  whe  a  supplied  with  wire-glass  windows 
and  safety  doors,  fire  can  be  confined  to  one  story.     They  are 
well  suited  for  forge  shops  or  wherever  open  fires  are  maintained. 

3.  Floors  can  be  made  waterproof,  and  during  a  fire,  water 
will  not  run  through  and  injure  goods  in  lower  stories.     For 
this  reason  all  openings  at  the  floor  should  have  a  3-in.  curb. 

4.  Concrete  buildings  are  durable.  •" 

5.  They  are  also  sanitary  and  can  be  washed  out  with  a  hose, 
being  well  suited  for  food  factories  or  packing  houses. 

6.  They   are   economical   in   cost.     As   they   often  need   no 
sprinkler  system  they  may  have  a  less  total  cost  than  wood. 
Construction  expense  is   reduced,  owing  to  the  possibility  of 
using  common  labor. 

7.  Local  labor  and  materials  can  generally  be  used  with  much 
saving  of  time,  for  no  delay  is  caused  in  waiting  for  structural 
timber  or  steel  from  a  distance. 

8.  They  can  be  easily  and  quickly  erected. 

9.  The  design  can  be  modified  at  any  time,  previous  to  or 
even  during  erection,  without  causing  expensive  delay. 

10.  The  thinner  walls  leave  a  greater  area  of  renting  space 
and  produce  less  load  on  the  foundations. 

11.  Vibrations  are  less  than  in  either  wood  or  steel  buildings. 

12.  Machines  can  run  at  higher  speeds  and  shafting  has  less 
friction  and  therefore  needs  less  power.     Wear  on  the  bearings 
is  also  less. 

13.  Concrete  buildings  make  a  larger  amount  of  wall  area 
available  for  windows. 

14.  Concrete  floors  are  not  affected  by  mineral  or  vegetable  oils. 

15.  They  are  vermin  proof,  for  rats,  mice  and  insects  can  find 
no  hiding  places  in  the  framing  as  in  timber. 

16.  They  have  a  low  heating  cost  and  an  even  temperature, 
being  warmer  in  winter  and  cooler  in  summer. 

Disadvantages  of  Concrete  Construction. — In  some  respects 
concrete  buildings  are  not  desirable,  some  of  their  disadvan- 
tages being  as  follows: 

1.  Changes  or  alterations  are  difficult  to  make  after  comple- 
tion.    Therefore,  since  concrete  is  hard  to  tear  down,  brick  walls 
should  be  used  where  extensions  are  anticipated. 

2.  When  outgrown,  they  have  little  or  no  salvage  value. 

3.  Thin  walls  and  floors  easily  transmit  sound,  and  in  certain 
places  these  must  be  double,  with  an  air  space  between  them. 


CONCRETE  FRAMING  105 

4.  The  merit  of  low  cost  may  in  some  cases  be  lost,  where 
instead  of  common  labor  the  regulations  of  trade  unions  may 
require  the  employment  of  bricklayers  or  men  at  equally  high 
wages  for  mixing  and  placing  the  concrete,  though  such  men 
may  reasonably  be  engaged  for  laying  concrete  blocks. 

5.  Shafting  and  machinery  are  not  so  easily  attached  to  the 
ceiling  and  floors  as  in  wooden  buildings. 

6.  Buildings  with   concrete  exterior  walls  usually  have   an 
unfinished    appearance,    unless    extra    expense    is    incurred    in 
special  treatment  of  the  surface,  or  unless  it  is  veneered  with 
some  other  material  such  as  brick. 

7.  Holes  or  openings  through  the  walls  and  floors  for  the 
accommodation  of  pipes  or  shafting  are  not  easily  made  after 
completion,  though  the  cutting  of  such  holes  may  be  no  more 
difficult  than  through  floors  of  brick  or  terra  cotta. 

8.  When  made  of  a  poor  quality  of  concrete  or  a  dry  mixture, 
the  walls  may  occasionally  be  found  damp  inside,  though  this 
condition  may  disappear  after  three  to  six  months  when  they 
become  well  dried. 

9.  The  effect  of   certain  destructive  agencies  on  reinforced 
concrete  has  not  yet  been  positively  determined.     Sea  water 
containing  salt  was  believed  to  have  a  disintegrating  effect,  but 
experience  so  far  shows  that  this  is  insignificant  (Cement  Age, 
Oct.  1911).     The  effect  of  electrolysis  on  concrete  is  not  well 
known  though  it  may  have  no  effect  whatever.     Water  contain- 
ing acid  in  solution  may  have  some  injurious  effect,  though  it  is 
probably  very  small.     Petroleum  and  engine  oil  produce  little 
or  no  effect  on  concrete,  but  those  containing  fatty  acids  appear 
to  be  injurious. 

10.  The  framing  members  have  a  large  size.     Columns  of  equal 
strength  in  different  materials  have  sizes  about  as  follows: 

Riveted  steel 8  X   8  in. 

Cast  iron 9  in.  round. 

Yellow  pine 12  X 12  in. 

Spruce. . 14 X 14  in. 

Concrete 18X18  in. 

Beams  and  girders  in  reinforced  concrete  are  proportionately 
large  when  compared  to  those  of  other  material.  The  objection 
to  this  is  that  the  large  columns  occupy  a  greater  amount  of  floor 
space,  leaving  a  smaller  renting  area.  This  may  be  important 


106     ENGINEERING  OF  SHOPS  AND  FACTORIES 

in  large  cities  such  as  Brooklyn,  where  rented  space  for  manu- 
facturing purposes  costs  25  to  30  cents  per  square  foot  of  floor 
area,  or  in  New  York  City,  where  it  rents  for  40  to  60  cents  per 
square  foot. 

Materials  and  Mixing. — The  three  kinds  of  modern  cement  are 
known  as  Natural,  Portland  and  Puzzolan  or  Slag  cement. 
Natural  cement  is  suitable  for  niasonry  with  only  compres- 
sive  stress,  Portland  being  used  for  nearly  all  other  cases. 
Puzzolan  cannot  be  put  in  any  important  work. 

Aggregates  may  be  either  fine  or  coarse.  !*ine  aggregate 
contains  sand,  gravel,  or  crushed  stone,  all  of  which  will  pass 
through  a  screen  with  1/4-in.  openings.  Mortar  composed  of 
three  parts  of  fine  aggregate  and  one  part  of  Portland  cement 
should  be  at  least  70  per  cent,  as  strong  as  that  made  from  one 
part  of  cement  and  three  of  clean  sand.  Coarse  aggregates 
should  preferably  contain  stone  of  assorted  sizes,  the  largest 


FIG.  59. — Plant  of  the  United  Shoe  Machinery  Co.,  Beverly,  Mass.     (F.  M. 
Andrews  &  Co.,  architects.) 

not  exceeding  2^  in.  in  diameter.  Natural  gravel  and  sand 
has  been  much  used,  as  in  the  original  building  for  the  United 
Shoe  Machinery  shops  at  Beverly,  Mass.  (Fig.  59)  though  on 
the  addition  of  1907,  crushed  stone  from  a  near-by  ledge  was 
used  instead.  A  good  proportion  for  concrete  in  floors  and 
walls  is  one  part  of  Portland  cement  with  six  parts  of  mixed 
aggregates,  though  a  richer  mixture  of  one  part  of  cement  with 
four  or  five  of  aggregate  is  better  in  columns,  while  a  poorer 
mixture  of  one  to  nine  or  twelve  parts  of  aggregate  is  enough  in 
foundations.  Cinder  concrete  is  good  only  for  fireproofing,  but 
not  for  any  important  structural  parts. 


CONCRETE  FRAMING  '  107 

Cement  is  supplied  either  in  bags  or  barrels,  the  latter  being 
most  suitable  when  dampness  is  present,  or  for  long  ocean  ship- 
ments. Bags  of  cement  weigh  95  Ib.  and  contain  about  1  cu.  ft. 
as  ordinarily  packed.  A  barrel  of  Portland  cement  contains 
four  bags  or  380  Ib.,  and  as  the  empty  barrel  weighs  about  20  Ib., 
the  total  weight  of  barrel  and  cement  is  400  Ib.  The  volume  of 
cement  depends  to  some  extent  cm  the  amount  to  which  it  is 
compressed,  and  barrels  may  be  made  to  contain  anywhere 
from  3J  to  4^  cu.  ft.,  though  3.8  cu.  ft.  weighing  95  Ib.  each, 
is  the  standard. 

Natural  cement  is  also  sold  in  bags  of  95  Ib.,  though  there 
are  only  three  bags  of  this  to  the  barrel,  which  weigh  altogether 
about  300  Ib. 

Rods  or  bars  should  be  medium  steel  with  elastic  limit  not 
exceeding  32,000  Ib.  per  square  inch,  though  wire  mesh  is  con- 
venient for  slabs,  and  for  reinforcing  structural  parts.  As  the 
metal  in  concrete  is  preserved  only  when  all  water  and  moisture 
are  excluded,  the  concrete  should  be  dense  enough  to  perform 
such  duty.  When  thoroughly  enclosed  and  protected,  the  metal 
is  safe  even  under  salt  or  fresh  water,  as  is  fairly  well  proven 
by  the  experiments  at  Boston  and  Charlestown  (Cement  Age, 
October  1911).  For  this  reason  cracks  should  be  avoided,  as 
steel  would  soon  be  destroyed  by  corrosion  when  water  enters. 
Experiments  to  ascertain  the  effect  of  paint  on  metal  for  rein- 
forcing concrete,  show  that  the  adhesion' of  concrete  to  steel  is 
decreased  90  per  cent,  when  metal  is  painted  with  red  lead,  and 
80  per  cent,  when  coated  with  oil.  It  shows  also  that  adhesion 
is  increased  from  30  to  40  per  cent,  when  the  metal  is  given  a 
coat  of  cement  grout,  mixed  thin  enough  so  one  pound  of  cement 
will  cover  when  applied  with  a  brush,  60  to  70  sq.  ft.  The  cost  of 
cement  coating  per  square  (100  sq.  ft.)  is  15  cents  for  one  coat 
and  22  cents  for  two  coats,  the  latter  being  equal  to  60  cents  per 
ton  of  ordinary  metal,  or  about  1  per  cent,  of  the  cost  of  the  steel 
in  place. 

The  barrel  is  the  most  convenient  unit  of  measurement  when 
mixing  concrete,  and  1  cu.  yd.,  or  27  cu.  ft.  contain  just  seven 
barrels.  A  mixture  which  is  suitable  for  foundations,  contains: 

7  barrels  of  broken  stone,  gravel,  etc.,  per  cubic  yard 
3  barrels  of  sand,  per  cubic  yard 
1^  barrels  of  cement,  per  cubic  yard 
25  gallons  of  water,  per  cubic  yard 


108-   ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  cost  of  such  concrete  will  frequently  not  exceed  $5  per  cubic 
yard,  while  a  corresponding  foundation  of  quarry  or  river  stone 
in  random  sizes  laid  in  cement,  might  cost  $8  per  yard,  though 
these  prices  will  depend  on  local  conditions. 

The  strength  of  concrete  of  different  ages  should  be  about  as 
follows : 

4* 

1  month,  crushing  strength,    4  tons  per  square  foot 
3  months,  crushing  strength,  10  tons  per  square  foot 
6  months,  crushing  strength,  16  tons  per  square  foot 
9  months,  crushing  strength,  21  tons  per  square"  foot 
12  months,  crushing  strength,  25  tons  per  square  foot 

Design. — The  four  types  of  construction  commonly  used  for 
concrete  buildings  are: 

1.  Reinforced  concrete  interior  frame  and  floors,  with  brick 
outside  walls. 

2.  Reinforced  concrete  interior  frame  and   floors,  with  con- 
crete walls. 

3.  Reinforced  concrete  interior  and  exterior  frame  and  floors, 
with  curtain-walls. 

4.  Light  self-supporting  steel  frame,  reinforced  with  concrete. 
Number  1  generally  has  the  best  appearance  and  is  well  suited 

to  small  buildings.  Number  2,  with  concrete  outside  walls  is 
difficult  to  make  attractive  in  appearance,  and  is  not  usually 
built  as  rapidly  as  number  1,  besides  costing  somewhat  more, 
though  it  is,  no  doubt,  more  rigid  than  either  1  or  3.  Number  3 
is  the  most  economical  design,  is  quickly  erected  and  can  be  made 
attractive  by  using  an  exterior  curtain  wall,  with  brick  veneer 
over  the  structural  parts.  Number  4  is  one  of  the  most  conven- 
ient types  of  reinforced  concrete,  and  might  better  be  called 
reinforced  steel  construction,  for  the  preliminary  light  steel  frame 
is  strengthened  with  concrete  after  erection  (Fig.  60) .  Concrete 
is  used  for  foundations,  columns,  sills,  lintels,  beams  and  floors, 
and  steel  for  trusses  and  heavy  girders  subject  to  jars  or  impact. 
Concrete  trusses  are  not  economical,  as  the  forms  are  expensive, 
and  they  are  not  reliable,  as  the  j  oints  are  .difficult  to  make.  The 
light  frames  of  structural  steel  should  be  heavy  enough  to  carry 
the  erection  loads  and  form  a  support  for  a  working  platform. 

The  same  amount  of  care  should  be  exercised  in  the  prepara- 
tion of  designs  and  plans  for  concrete  buildings  as  is  usually 
given  to  structural  steel.  Stress  sheets  should  show  separately 
all  loads,  dead,  live,  impact  and  wind.  Specifications  should 


CONCRETE  FRAMING 


109 


give  the  proportion  of  materials  in  different  mixtures,  and  the 
strength  that  concrete  is  assumed  to  have  at  the  end  of  a  stated 
period.  The  ultimate  merit  of  a  concrete  building  will  depend 
largely  upon  the  use  of  correct  designing  principles,  good  details, 
safe  units,  careful  calculations,  proper  quality  of  materials  and 
careful  erection.  It  has  long  been  an  axiom  of  structural  design 
that  strength  and  durability  depend  on  the  details,  and  this  is 
quite  as  true  of  concrete  framing  as  of  steel.  All  details  should 
be  plainly  shown,  even  minor  ones,  and  sizes,  position  of  rein- 


Connections  of 

Beams  to  Girders. 


forcement,  etc.,  all  properly  studied  out.  Special  attention 
should  be  given  to  the  joints  and  provision  made  for  tempera- 
ture changes,  shrinkage  after  placing,  and  waterproofing. 
Plans  and  specifications  should  be  signed  in  duplicate  by  engi- 
neers or  contractors,  and  these  parties  should  be  held  respons- 
ible for  the  safety  of  the  building,  even  though  the  plans  are 
afterward  approved  by  city  authorities  or  others. 

Fine  theory  is  of  less  importance  in  concrete  construction 
than  in  steel,  owing  to  the  coarser  nature  of  the  materials,  and 
simple  formulae  are  preferable  to  complicated  ones.  As  the 
assumptions  on  which  certain  formula  are  based  may  never  be 
realized  within  100  per  cent,  it  is  plainly  useless  to  aim  at  exact 
proportioning.  Attention  should  be  given  to  essentials,  and 
trifles  neglected  or  lightly  treated. 


110     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Protection  should  be  made  against  injury  from  fire  by  the 
burning  of  a  building's  contents.  Concrete  is  partly  decomposed 
at  a  temperature  of  900  to  1000°  F.,  but  the  injured  material 
remains  in  place  and  forms  a  protection  for  the  part  beneath  it. 
The  new  Chicago  Building  Law  gives  separate  rules  for  buildings 
of  different  heights,  those,. of  90  ft.  or  more,  known  as  fireproof, 
may  be  designated  as  Class  A  and" lower  buildings  or  non-fire- 
proof ones  as  Class  B. 

CLASS  A  BUILDINGS 

Columns,  beams  and  girders  must  have  not  less  than  2-in. 
covering  over  the  metal. 

Slabs  must  have  a  covering  of  not  less  than  1  in.  below  the 
metal. 

CLASS  B  BUILDINGS 

Columns,  beams  and  girders  must  have  not  less  than  1J  in. 
covering  over  the_metal. 

Slabs  must  have  a  covering  of  not  less  than  ^  in.  below  the 
metal. 

As  the  effect  of  fire  on  concrete  has  seldom  been  found  to 
penetrate  deeper  than  j  in.  even  in  great  conflagrations,  the 
provisions  given  above  are  large  enough,  and  agree  closely  with 
the  practice  recommended  by  the  Joint  Committee  on  Rein- 
forced Concrete.  The  additional  concrete  specified  above  is 
for  fire  protection  only,  and  should  not  be  considered  as  resisting 
any  direct  stresses,  though  in  many  cases  it  actually  does  add  to 
the  strength  of  the  members. 

During  construction,  and  after  completion  the  building  should 
be  inspected  by  the  engineers  or  their  representatives,  and 
special  examination  made  of  the  following  features : 

1.  Compare  size  of  members  and  reinforcing  with  that  shown 
on  drawing. 

2.  Quality  and  proportion  of  materials  and  methods  of  mix- 
ing them. 

3.  Nature  of  forms  and  hardness  of  concrete  before  removing 
them. 

4.  Protection  against  injury  after  forms  are  removed. 

5.  Application  of  test  load  on  some  of  the  weakest  parts,  two 
months  after  completion. 


CONCRETE  FRAMING  111 

Working  Units. — When  proportioning  members,  working  unit 
stresses  should  be  used  as  in  steel  framing,  rather  than  ultimate 
values,  as  proposed  by  some,  and  these  units  should  be  low  enough 
to  be  well  under  the  danger  line. 

Stone  concrete  with  an  ultimate  compressive  strength  of 
2000  Ib.  per  square  inch  after  twenty-eight  days,  may  have  the 
following  working  units: 

Plain  concrete  in  columns,  not 

reinforced Compression,  400  Ib.  per  square  inch. 

Reinforced  concrete Compression,  600  to  750  Ib.  per  square  inch. 

Compression  in  outer  edge  of 

beams Compression,  500  Ib.  per  square  inch. 

If  the  compressive  unit  in  columns  with  vertical  reinforcing  only, 
is  represented  by  U,  the  working  stress  may  be  increased  by  20 
per  cent,  when  hoops  only  are  used,  and  by  45  per  cent,  if  the 
column  has  both  vertical  reinforcing  and  spiral  winding.  Ten- 
sion in  concrete  should  in  most  cases  be  ignored. 

Adhesion. — The  ultimate  adhesion  value  of  concrete  to  clean 
steel  is  500  to  600  Ib.  per  square  inch,  but  working  stresses  should 
not  exceed  60  to  80  Ib.  per  square  inch  for  plain  bars,  and  30  to 
50  Ib.  for  wire. 

The  working  shearing  stress  in  concrete  that  is  not  reinforced, 
should  not  exceed  40  Ib.  per  square  inch,  though  60  Ib.  is  per- 
missible with  partial  reinforcing,  and  120  Ib.  per  square  inch 
when  fully  reinforced. 

Tensile  stress  in  reinforcing  bars  should  not  exceed  14,000 
Ib.  per  square  inch  in  soft  steel,  and  16,000  in  medium  steel. 
The  permissible  compressive  strength  of  cinder  concrete  at  the 
end  of  30  days,  does  not  exceed  700  to  900  Ib.  per  square  inch, 
and  its  weight  is  usually  about  110  Ib.  per  cubic  foot. 

Separately  Moulded  Members. — In  this  type  of  construction, 
the  parts  are  moulded  either  at  the  site  or  in  a  factory  and  then 
shipped  to  the  building,  the  former  method  usually  being  the 
cheaper.  A  number  of  types  have  been  devised  including  the 
Siegwart,  Vaughan,  Armoured  Tubular,  Climax,  Unit,  Standard 
and  Watson  systems.  Some  of  these  relate  only  to  the  floors, 
others  only  to  the  frames,  while  some  include  both.  The  Sieg- 
wart system  of  hollow  concrete  beams  (Fig.  61),  though  origin- 
ally a  European  product,  is  manufactured  also  at  Montreal, 
Canada,  the  cost  of  floor  when  erected  varying  from  17  to  26 
cents  per  square  foot,  depending  on  the  span  and  load  specified. 


112     ENGINEERING  OF  SHOPS  AND  FACTORIES 


The  Armoured  Tubular  system  (Fig.  62)  is  an  English  product 
costing  about  22  cents  per  square  foot.  Climax  beams  (Fig.  63) 
are  made  in  Chicago,  and  the  Unit,  Standard  (Fig.  62a),  and 
Watson  systems  (Fig.  63  a)  are  also  American. 

Separately  moulded  members,  when  factory  made,  have  the 


*-/z-^ 


FIG.  61. — Seigwart  floor  beams 
Standard  Sect.  No.  21. 


FIG.  61a. — Vaughan  system. 


advantage  that  the  proportion  of  materials  can  be  more  exact 
and  the  members  can  be  tested  before  erection.  They  are  more 
reliable,  and  higher  working  stresses  may  therefore  be  allowed, 
with  a  corresponding  decrease  in  materials  and  weight.  They 
need  fewer  forms  than  monolithic  work  and  this  item  of  expense 


FIG.  62. — Armoured  tubular  system.  FIG.  62a. — Standard  system. 

is,  therefore,  comparatively  small.  They  can  be  quickly  erected 
and  alterations  after  completion  are  more  easily  made  with 
separate  members  than  with  solid  construction,  the  former 
being  more  like  other  block  structures. 

(fie/a 'Concrete 


FIG.  63. — Climax  system. 


FIG.  63a.— Watson  system  "A.' 


The  disadvantages  of  buildings  made  of  separately  moulded 
members,  are: 

1.  Lack  of  rigidity,  and  (2)  increased  amount  of  reinforcing 
metal.  The  first  of  these  objections  disappears  to  some  extent 
when  the  parts  are  well  connected  with  dowels  and  cement. 


CONCRETE  FRAMING 


113 


•#ov*H  ft.ao*s 

FIG.  64. — Detail  of  Watson  system.     Separately  moulded  beams. 


FIG.     65. — Detail    of    Watson    system.     Separately    moulded    members, 

combined  slab  and  beam  construction. 
8 


114     ENGINEERING  OF  SHOPS  AND  FACTORIES 


The  increased  amount  of  reinforcing  metal  is  due  chiefly  to  a 
lack  of  continuity  in  beams  and  slabs,  and  is  a  condition  which 
is  not  easily  overcome. 

The  following  table  gives  comparative  weights  per  square 
foot  of  floor  for  all  materials,  including  reinforcing  metal,  in 
concrete  floors  of  different  types. 


Weight  of  all 
materials 
Ibs. 

Weight  of  steel 

Ibs. 
t 

Flat  slabs  

96 

3  75 

Concrete  and  tile  (Kahn  system)  
Slab  and  beam  

72 
56 

2.77 
2  41 

Terra-cotta   arches  with   concrete  top 
between  steel  beams. 
Watson  system  

55     . 
45 

5.4 
2  75 

Concrete  structural  members  are  conveniently  made  at  the 
building  site  by  first  laying  the  shop  floor,  which  may  then  be 
used  as  a  working  platform  on  which  to  make  the  pieces  for  the 
superstructure.  Slabs  may  be  cast  in  piles  with  nothing  more 
than  heavy  waxed  manila  paper  between  them,  which  is  easily 
removed  after  erection  by  a  jet  of  water  from  a  hose.  The 
pieces  may  be  slightly  offset  in  the  piles  to  facilitate  handling. 
When  the  concrete  in  the  members  has  hardened,  they  can  be 
erected  with  a  stiff  leg  derrick  or  a  traveling  crane  at  a  cost  for 
hoisting  which  should  not  exceed  $1  per  ton. 

The  relative  cost  of  buildings  of  the  monolithic  and  separately 
moulded  types  can  best  be  shown  by  a  comparison  of  two  dupli- 
cate ones  built  for  the  Central  Pennsylvania  Traction  Company. 

It  appears,  therefore,  that  the  building  with  separately 
moulded  members  cost  $2.185  per  cubic  yard  of  concrete,  less 
than  the  monolithic  building.  To  offset  this  saving,  the  building 
with  separately  moulded  members  contained  20  per  cent,  more 
material  than  the  other,  but  even  so,  the  net  saving  in  favor  of 
the  building  with  separate  members  was  15  per  cent. 

The  addition  to  the  United  Shoe  Machinery  Company's 
building  at  Beverly,  Mass.,  which  has  separately  moulded 
framing  members  cast  on  the  ground,  but  monolithic  floors, 
showed  a  saving  of  10  per  cent,  over  the  original  building,  which 


CONCRETE  FRAMING 

TABLE   VII 


115 


Materials  and  labor 

Cost  pe 

r  cubic  yard 

Monolithic 

Separately  moulded 

Materials: 
Stone,  sand  and  cement  

$3  480 

$3  480 

Reinforcement   

915 

1  140 

Lumber  

1  335 

480 

Paper               

000 

040 

Tools 

145 

145 

Total  material  

$5  875 

$5  285 

Labor: 
Carpentry  work   .         .        .... 

3  250 

965 

Bending  and  placing  

095 

230 

Concreting        .                        .  . 

2  210 

1  685 

Erection  

.000 

1  080 

Total  labor  

$5  .  555 

$3  960 

Total  material  and  labor  

$11.430 

$9  .  245 

was  wholly  monolithic,  both  the  addition  and  the  original 
being  built  under  the  direction  of  Mr.  Ernest  Ransome.  The 
cost  of  grouting  the  face  after  completion  was  1  cent  per  square 
foot. 

Comparative  costs  are  also  available  for  two  other  buildings 
of  separate  members,  namely,  the  Textile  Machine  Works  of 
Reading,  Pa.,  and  the  Edison  Portland  Cement  Company's  build- 
ings. The  plant  at  Reading  cost  80  cents  per  square  foot  of 
floor  for  the  frame  and  floor  only,  without  curtain  walls,  finish 
or  engineering  charges,  and  25  per  cent,  of  this  cost  was  for 
carpentry  labor  and  forms.  The  building  when  completed  cost 
only  7.7  cents  per  cubic  foot.  The  Edison  Portland  Cement 
Company's  building  is  one  story  high,  144  ft.  wide  and  360  ft. 
long,  with  32-ft.  columns  and  24-ft.  girders,  all  made  at  the 
building  site.  The  cost  of  making  and  erecting  the  concrete 
was  only  $6.60  per  cubic  yard,  which  is  extremely  low,  and 
could  hardly  be  reproduced  at  less  than  $7.50  to  $8.  Cement 
cost  $1  per  barrel,  and  crushed  stone  60  cents  per  cubic  yard. 


116     ENGINEERING  OF  SHOPS  AND  FACTORIES 


The  cost  of  4-in.  slabs  in  place,  when  moulded  in  a  horizontal 
position  previous  to  erection,  is  about  as  follows: 

Cost,  cents  per 
100  sq.  ft. 

Steel 2 . 36  equal  to  30      per  cent,  of  total 

Concrete  labor 2 . 55  equal  to  32      per  cent,  of  total 

Carpenter  labor !  . : 5#  equal  to    7.5  per  cent,  of  total 

Labor,  mixing  and  placing 56  equal  to    7       per  cent,  of  total 

Erection 1 . 86  equal  to  23 . 5  per  cent,  of  total 


7.91  equal  to  100.  'per  cent,  of  total 

Columns. — Three   kinds   of   columns   are  ordinarily  used   in 
concrete  buildings. 

1.  Columns  with  vertical  reinforcing  only. 

2.  Columns  with  vertical  reinforcing  and  hoops. 

3.  Columns  with  light  structural  steel  frames. 

Square  columns,  even  in  the  upper  stories,  seldom  have  less 
than  12-in.  sides,  and  the  corners  usually  have  a  1-inch  champ- 

fer.  The  general  practice  is 
to  use  square  columns  with 
only  four  vertical  reinforcing 
rods  for  sizes  of  16  to  18  in. 
In  lower  stories  where  greater 
strength  is  needed,  hoops  or 
spiral  winding  may  be  used, 
in  which  case  an  octagonal 
form  with  eight  rods  is  pre- 
ferred. Columns  in  walls  may 
have  a  uniform  thickness 
through  several  stories,  in- 


FIG.  66. — Spiral  reinforcing  for 
columns. 


creased  sectional  area  being 
secured  by  a  change  in  width. 
A  mixture  of  cement,  sand 

and  stone,  in  the  proportions  of  1,  1^  and  3,  is  the  best,  and 
stone  should  generally  not  exceed  1  in.  in  diameter.  Columns 
should  be  reinforced  when  their  length  exceeds  six  times  their 
diameter,  and  when  extra  material  is  added  for  fireproofing,  only 
the  area  inside  of  the  fireproofing  should  be  considered  as  sustain- 
ing loads.  The  maximum  column  length  should  never  exceed 
fifteen  times  the  inside  diameter.  An  additional  thickness  of 
1  to  3  in.  over  the  structural  part  should  be  allowed  for  fire- 
proofing  as  previously  described  under  "  Design." 


CONCRETE  FRAMING  117 

Vertical  reinforcement  when  used,  may  vary  from  1  to  5 
per  cent,  of  the  inside  column  area,  the  average  being  about 
2  per  cent.  Four  rods  are  most  convenient  in  square  columns, 
and  eight  in  octagonal  ones,  and  bars  are  quite  as  good  plain  as 
when  roughened.  They  should  be  spliced  just  above  the  floor 
level  with  butt  joints,  and  the  bars  surrounded  with  sections  of 
pipe  about  12  in.  long,  and  1/4  in.  larger  inside  than  the  diam- 
eter of  the  rod.  Footing  plates  should  be  placed  under  the  rod 
at  the  base  of  the  columns,  and  these  plates  should  be  large 
enough  to  distribute  their  portion  of  the  load.  Column  hooping 
(Fig.  66)  may  consist  of  either  bands  or  spirals,  the  latter  being 
conveniently  made  of  round  bars  from  3/16-  to  1/2-  in.  diameter 
with  a  pitch  of  2  to  4  in.,  the  spacing  being  maintained  by  flat 
bars  notched  at  the  proper  interval.  Bands  when  used  may  be 
spaced  from  4  to  20  in.  apart,  the  usual  practice  being  12  in. 

The  cost  of  columns  18  in.  square  per  foot  vertical  is  about  as 
follows : 

Concrete $0 . 55  per  vertical  foot 

Steel 75  per  vertical  foot 

Forms 50  per  vertical  foot 


Total $1 .80  per  vertical  foot 

The  most  economical  column  spacing  depends  upon  the  loads 
and  the  kind  of  floor  construction.  For  250  Ib.  per  square  foot 
or  less,  the  economical  column  spacing  for  two  different  floor 
types  is: 

Floor  with  beams  and  girders 18  X 18  ft. 

Floor  with  flat  slabs ....   20  X  20  ft. 

For  loads  of  300  Ib.  per  square  foot  or  more,  the  column  spacing 
for  the  above  types  is: 

Floors  with  beams  and  girders 15  X 15  ft. 

Floors  with  flat  slabs 17  X 17  ft. 

Beams. — Experiments  show  that  reinforced  concrete  beams 
are  at  least  ten  to  twelve  times  stronger  than  beams  which  are 
not  reinforced.  They  are  generally  suitable  in  building  frames, 
but  in  some  places,  such  as  crane  girders,  subject  to  frequent  and 
heavy  jars  and  impact,  steel  framing  is  more  reliable.  And 
yet  reinforced  concrete  beams  have  occasionally  been  used 
even  for  crane  girders,  as  illustrated  in  the  shop  for  the  Ingersoll 
Milling  Machine  Company  at  Rockford,  111. 


118     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  cross-sectional  outline  of  concrete  beams  is  usually  rec- 
tangular, or  in  the  form  of  a  broad  T.  A  good  proportion  for 
rectangular  beams  is  to  make  the  depth  from  one-tenth  to  one- 
twelfth  of  the  span  length,  and  the  width  from  one-half  to  three- 
fourths  of  the  depth.  Deep  and  narrow  beams  contain  less 
material  and  are  proportionately  cheaper  than  wide  and  shallow 
ones.  T-beams  are  really  ribbed  "or  stiffened  slabs,  the  com- 
pression being  resisted  by  the  slab,  and  the  tension  by  bars  in 
the  lower  part  of  the  stem,  the  concrete  stem  acting  like  the 
compression  braces  in  trussed  beams  to  separate' the  rods  from 
the  compression  chord.  The  proportioning  of  T-beams  is  at  the 
best  only  a  rough  approximation,  for  it  is  impossible  to  know 

.    how  great  a  width  of  slab  is 


i 


I  Not  more  than 

r< 4-t— 


subjected  to  compression. 
The  common  practice  is  to  as- 
sume the  breadth  of  T-beams 


(Fig.  67)  as  not  more  than 
one-fourth  of  the  span,  and 
the  distance  at  each  side  from 

the  stem  to  the  edge  of  the 
FIG.  67. — T-beam. 

compression     flange     as    not 

more  than  four  times  the  slab  thickness.  The  width  of  the 
stem  is  frequently  assumed  at  one-third  to  one-fifth  of  the  slab 
width.  If  the  stem  were  wide  enough  there  would  be  no  need 
of  assuming  any  part  of  the  slab  in  compression.  It  is,  there- 
fore, inconsistent  to  attempt  fine  proportioning  in  concrete 
beams  of  any  kind,  for  the  nature  of  the  material  and  the 
primary  assumptions  are  such  as  to  make  these  efforts  useless. 
While  the  coefficient  of  elasticity  for  steel  is  quite  close  to 
30,000,000,  that  for  reinforced  concrete  varies  anywhere  from 
1,500,000  to  5,000,000,  and  their  relative  proportions  or  the 
value  usually  designated  by  the  letter  N,  varies  accordingly 
from  6  to  20.  Some  other  assumptions  have  quite  as  large  a 
variation.  The  complicated  beam  formulae  proposed  by  some 
writers,  are,  therefore,  not  only  absurd,  but  an  actual  waste  of 
time,  and  simple  formulae  only  are  appropriate. 

Since  the  compression  in  slabs  and  beams  is  usually  resisted 
wholly  by  the  concrete,  joints  in  these  members  should  be  made 
near  the  center  of  the  span.  In  this  position  cracks  are  of  little 
consequence,  but  near  the  end  in  the  region  of  maximum  shear, 
they  are  serious.  When  a  condition  of  continuity  exists,  it  is 


CONCRETE  FRAMING 


119 


customary  to  assume  the  bending  moment  as  25  per  cent,  less 
than  for  simple  beams  supported  at  the  ends.  The  formulae  for 
continuous  beams  are 

WL* 
M=-y^-  for  intermediate  spans 

WL* 
M  =  -T/r-  for  end  spans 

where  M  is  the  bending  moment  in  foot-pounds 

W  the  load  in  pounds  per  lineal  foot 

L    the  length  of  span  in  feet. 

When  square  panels  are  reinforced  in  two  directions,  one-half 
of  the  above  stresses  should  be  considered  in  each  system. 

Beam  and  girder  reinforcement  are  less  expensive  and  more 
effective  when  made  into  unit  frames  (Fig.  68)  in  a  metal  shop 
than  when  loose  bars  are  assembled  in  the  beams  at  the  build- 
ing site.  Enough  reinforcement  should  be  used  to  prevent 


FIG.  68. — Unit  girder  frame. 

deflection,  for  when  this  occurs  cracks  will  form,  which  may 
admit  enough  water  or  moisture  to  ultimately  destroy  the  bars 
with  rust.  Beams  may  have  from  two  to  eight  reinforcing  rods 
and  rods  should  not  be  closer  together  horizontally  than  2£ 
to  3  diameters  and  the  clear  space  between  two  layers  of  bars 
should  not  be  less  than  1/2  in.  The  distance  from  the  center 
of  a  bar  to  the  bottom  or  sides  of  beam  should  not  be  less  than 
two  diameters  of  the  bar,  in  order  to  secure  a  good  bond  and  to 
protect  the  metal  from  fire.  The  bond  between  concrete  and 
steel  depends  wholly  upon  the  contraction  of  the  concrete 
when  hardening,  during  which  process  it  forms  a  grip  on  any 
material  embedded  therein.  There  is  no  chemical  affinity  or 


120     ENGINEERING  OF  SHOPS  AND  FACTORIES 

union,  for  if  cement  or  concrete  is  placed  on  a  metal  surface  and 
allowed  to  harden,  it  can  very  easily  be  broken  off.  The  con- 
crete must,  therefore,  surround  the  metal  in  order  to  form  a 
grip.  Plain  unpainted  bars,  either  round  or  square,  are  the  best 
and  a  slight  coat  of  rust  is  no  disadvantage.  Bars  should  not 
be  spliced  at  the  point  of  maximum  stress,  and  the  length  of 
lap  will  depend  on  the  amount  of  Stress  at  the  point  of  splice 
and  the  assumed  adhesive  unit.  Sharp  bends  in  shear  rods 
must  be  avoided,  and  diagonals  should  have  effective  end 
anchorage. 

Stirrups  (Fig.  69)  have  been  found  to  increase  the  shearing 
strength  of  beams  by  300  to  400  per  cent.  Their  distance  apart 
longitudinally  should  generally  not  exceed  three-quarters  of 


FIG.  69.  —  Stirrups  for  reinforced  concrete. 

the  beam  depth,  and  they  should  be  connected  to  the  horizontal 
rods.  A  good  empirical  rule  is  to  use  four  stirrups  at  each  end 
of  concrete  beams,  spaced  about  as  follows:  Place  the  first 
stirrup  one-quarter  of  the  beam  depth  from  the  end,  and  the 
second,  third  and  fourth  should  follow  at  distances  of  one-half, 
three-fourths,  and  once  the  depth  of  the  beam  in  each  case  from 
the  preceding  ones.  A  vertical  sheet  of  expanded  metal  or  wire 
mesh  may  be  used  instead  of  the  stirrup  bars. 

An  original  formula  devised  by  the  writer,  for  concrete  beams, 
which  is  easily  applied  and  yet  safe,  is  as  follows: 


where  D  =  depth  of  beam  in  inches,  from  the  upper  surface  to 
the  center  of  the  rods 


CONCRETE  FRAMING  121 

M  =  bending  moment  in  inch  pounds 
C  =  a  factor  varying  from  60  to  150,  but  usually  taken 

at  100. 
B  =  breadth  of  beam  in  inches. 

The  cost  per  lineal  foot  of  concrete  joists,  6X12  in.,  is  about 
as  follows: 

Concrete  and  steel $0 . 45  per  lineal  foot. 

Forms 25  per  lineal  foot. 


Total 70  per  lineal  foot. 

The  cost  per  lineal  foot  for  reinforced  concrete  girders,  12  X 
20  in.,  is: 

Concrete  and  steel $0.60  per  lineal  foot. 

Forms 35  per  lineal  foot. 


Total  .95  per  lineal  foot. 

Reports  on  the  cost  of  concrete  of  1-2-4  mixture,  in  a  number 
of  large  buildings,  showed  that  for  the  concrete  alone  without 
forms  or  reinforcing  metal,  the  average  cost  of  concrete  in  floors 
was  $6.10  per  cubic  yard,  and  in  the  columns,  $6.70  per  cubic 
yard,  when  cement  cost  $1.35  per  barrel,  and  sand  and  crushed 
stone,  80  cents  and  $1.25  per  cubic  yard  respectively.  Plant 
rental,  coal,  and  power  cost  from  50  cents  to  $1.50  per  cubic 
yard  of  concrete. 

The  above  data  is  based  on  Chicago  prices  in  1911,  and  should 
be  carefully  modified  to  suit  the  local  price  of  labor  and  mate- 
rials, variations  in  which  may  cause  great  changes  from  the 
above  approximate  costs. 

Machinery  Connection  to  Concrete  Floors. — Connections  to 
shop  floors  differ  according  to  the  size  and  weight  of  the  machines. 
The  best  practice  for  heavy  machines  is  to  raise  them  about  ^ 
in.  above  the  floor  and  to  run  in  thin  grout  to  a  width  of  4  to  5 
in.  all  around.  Light  machines  with  insufficient  weight  to  hold 
them  in  place  must  be  fastened  to  the  floor  by  expansion  bolts 
set  in  holes  1^  to  3  in.  deep,  drilled  into  the  slab,  a  shield 
being  used  when  drilling,  to  prevent  the  tool  from  going  through 
the  floor.  In  other  cases,  machines  have  been  bolted  through 
the  floor  slab  and  fastened  with  nuts  and  washers  on  the  under 
side.  Very  light  machines  may  sometimes  be  screwed  down  to  a 
temporary  wood  floor  placed  over  the  concrete. 


122     ENGINEERING  OF  SHOPS  AND  FACTORIES 


food  Filler 


hor  Bolt  B 


Girder 


T"  Cast  Iron       JHjjT' Headed  Bolts*  \  Angle 
Clamp  for  Attaching  ^3 

-•+     Hangers  etc. 


LU-1 

I 

1 

M  ill 

r  --—---&  =  —  -=-&.--  

1 

B 

D 

( 

Wood  Pill* 

Angle 

ron  Clamp 

Anchor  Bolt 

'T"Headed  Attaching 

Bolt,  in  Slot 


Cast  Iron      _  ^^ 

Clamp  Attaching  Bolt 


Pipe 


FIG.  70. — Connections  to  concrete  beams. 


CONCRETE  FRAMING  123 

Shafting  Attachment. — There  are  a  number  of  good  methods 
in  use  for  attaching  shafting  to  the  under  side  of  concrete  beams 
and  floors  (Fig  70)  and  other  details  can  easily  be  devised  as 
needed  to  suit  special  cases.  If  no  provision  was  made  for  such 
attachments  when  the  building  was  first  erected,  holes-can  then 
be  tapped  for  expansion  bolts,  using  a  portable  air  drill.  This 
machine  works  quickly  and  at  very  small  cost. 

When  connections  are  planned  beforehand,  holes  may  then  be 
left  2  to  3  ft.  apart  through  the  beams  beneath  the  floor,  and  in 
flat  floors  without  beams,  cast-iron  spool  sockets  can  be  set  into 
the  ceiling.  Holes  in  the  walls  and  floors  for  plumbing  and  heat- 
ing pipes  should  have  cast-iron  spools  or  sockets  and  they  should, 
.  if  possible,  be  placed  during  first  construction.  For  this  purpose 
subcontractors  for  plumbing  and  heating  should  supply  the  con- 
crete contractor  with  a  plan  showing  the  size  and  position  of 
all  such  openings. 

Waterproofing. — Concrete  made  with  wet  mixture  is  imper- 
vious to  water,  and  walls  of  this  kind  with  no  greater  thickness 
than  8  in.  and  without  any  waterproofing  may  safely  be  used  for 
cellars  and  basements.  It  is  only  when  concrete  is  made  too 
dry  that  walls  are  pervious.  Concrete  blocks  which  often  have 
a  dry  mixture  in  order  to  make  them  quickly  are  subject  to  this 
objection.  Condensation  is  likely  to  form  in  basements  or  other 
damp  places,  but  this  can  be  avoided  by  lath  and  plaster  over 
furring.  Where  there  is  danger  of  crack  formation  from  tem- 
perature changes  or  other  causes,  metal  reinforcement  should  be 
used.  This  will  prevent  the  formation  of  large  cracks  and  pro- 
duce a  larger  number  of  small  ones  so  narrow  that  moisture 
cannot  enter. 

Waterproofing  may  be  necessary  to  prevent  moisture  from 
soaking  into  the  joints  and  freezing,  thereby  tending  to  disin- 
tegrate the  masonry.  It  may  be  necessary  also  to  prevent 
water  leaking  through,  and  discoloring  or  otherwise  disfiguring 
the  interior  of  the  building.  Waterproofing  may  be  affected  in 
several  ways. 

1.  By  making  a  rich  and  wet  outer  mixture  of  mortar  with 
equal  parts  of  Portland  cement  and  sand.     On  horizontal  sur- 
faces this  can  be  laid  as  granolithic  with  a  troweled  surface  on  a 
wet  or  green  base,  at  a  cost  of  about  5  cents  per  square  foot. 

2.  By  covering  the  outer  surface  of  the  concrete  with  layers 
of  waterproof  felt  coated  with  asphaltum. 


124     ENGINEERING  OF  SHOPS  AND  FACTORIES 


3.  By  replacing  10  per  cent,  of  the  cement  with  hydrated 
lime,  to  assist  in  filling  voids  and  making  the  concrete  more 
nearly  impervious. 

Erection. — Reinforced  concrete  buildings  should  be  erected 
under  at  least  the  partial  direction  of  the  designer.  In  cold 
weather,  material  may  be -heated  bv,  piling  it  over  steam  pipes, 
the  material  pile  being  covered  with  canvas,  and  during  working 
hours  the  part  under  construction  may  be  enclosed  by  a  curtain 
under  which  heat  is  maintained. 

In  joining  new  work  to  old,  the  hardened  surface  should  first 
be  cleaned  till  the  aggregate  is  well  exposed,  and  it  should  then 
be  slushed  with  mortar  consisting  of  one  part  of  Portland  cement 


i  &  Rolled  Cinder  Fill  ••*  fn 

•^  «sfe        ^          i    •  , 

Cross    Sectiorl. 

FIG.  71. — Reinforced  concrete  warehouse,  Chicago. 

with  two  parts  of  fine  aggregate,  before  placing  the  new  con- 
crete. Expansion  joints  should  be  provided  at  intervals  not 
exceeding  50  ft.,  and  they  should  have  overlapping  or  dovetailed 
joints.  The  concrete  should  be  carefully  inspected  for  hardness 
before  the  forms  are  removed.  After  the  foundations  are  com- 
pleted, reinforced  concrete  buildings  can  usually  be  erected  at 
the  rate  of  one  story  per  week,  and  records  show  that  large 
buildings  to  six  to  twelve  stories  can  be  erected  complete  in 
three  to  seven  months. 

Fig.  71  shows  a  concrete  machinery  warehouse  in  Chicago,  with 
one  tier  of  side  gallery. 


CHAPTER  IX 
CONCRETE  SURFACE  FINISH 

The  difficulty  of  producing  esthetic  and  pleasing  effects  has 
until  recently  been  one  of  the  chief  objections  to  concrete  as  a 
structural  material  in  exposed  positions.  The  many  primitive 
and  uncouth  productions  of  the  experimental  years  of  its  devel- 
opment, are  still  too  evident  about  our  large  cities,  and  these 
obnoxious  creations  have  often  turned  prospective  builders  to 
other  and  more  attractive  types.  Factory  buildings  with  bare 
gray  walls,  the  monotony  of  which  is  broken  only  by  unsightly 
form  marks  are  rightly  entitled  to  disapproval.  Many  of  these 
buildings  were  erected  before  the  methods  of  surface  treatment 
were  developed,  while  others  are  the  result  of  supposed  economy 
or  deliberate  disregard  for  appearances. 

Surface  Defects. — Some  of  the  surface  imperfections  of  con- 
crete which  must  be  avoided  or  removed,  include  efflores- 
cence, cracks,  irregularity  of  section,  roughness,  porosity,  and 
dusting. 

Efflorescence  is  supposed  to  result  from  a  porous  condition  of 
the  walls,  allowing  moisture  to  enter,  for  it  is  not  found  in  dry 
positions.  It  would,  therefore,  appear  desirable  that  walls  be 
water  tight,  and  methods  of  waterproofing  concrete  have  already 
been  given  in  a  previous  chapter.  The  most  notable  case  of 
efflorescence  removal  is  on  the  Connecticut  Avenue  bridge  at 
Washington.  Hydrochloric  acid,  diluted  with  five  parts  of 
water,  was  applied  to  the  surface  with  scrubbing  brushes,  30 
gallons  of  acid  and  thirty-six  brushes  being  used  in  cleaning 
250  sq.  yds.  The  average  cost  of  the  whole  work,  including  the 
balustrades  was  7  cents  per  square  foot,  but  on  plain  surfaces 
the  cost  did  not  exceed  2£  cents  per  square  foot. 

Hair  Cracks. — The  best  means  of  preventing  hair  cracks  is  to 
use  a  comparatively  dry  and  lean  mixture  not  richer  than  one 
part  of  cement  with  four  of  sand,  for  it  has  been  found  that 
they  increase  rapidly  with  the  proportion  of  cement.  These 

125 


126     ENGINEERING  OF  SHOPS  AND  FACTORIES 

cracks  are  caused  by  cement  on  the  surface  hardening  and 
shrinking  more  rapidly  than  that  inside,  and  they  can  be  partly 
avoided  by  keeping  the  surface  covered  with  wet  sand  or  saw 
dust.  They  are  almost  entirely  absent  on  fine  artificial  stone, 
which  is  moulded  in  wet  sand. 

Porosity. — Porosity  is  caused  by  a  lack  of  density,  and  if  the 
outer  and  hardest  layer  is  removed^  the  surface  is  more  likely 
to  leak.  Walls  which  will  admit  water  are  liable  to  be  disinte- 
grated by  frost  in  winter  seasons,  and  the  outer  surface  should 
not,  therefore,  be  removed  in  cold  climates. 

Dusting. — This  may  be  due  to  several  causes,  some  of  which 
are:  Insufficient  cement,  soft  sand,  presence  of  foreign  matter 
such  as  loam,  poor  mixing,  partial  setting  of  cement  before 
finishing,  excess  of  or  not  enough  water  in  the  surface  mixture, 
or  the  use  of  driers  to  hasten  setting.  After  such  a  condition 
has  developed,  it  can  best  be  remedied  by  applying  two  or  three 
coats  of  boiled  linseed  oil. 

Forms  and  Moulds. — Defects  from  forms  and  moulds  are 
very  common,  and  include  irregularities  from  bulging  or  spring- 
ing of  the  plank,  joint  marks  or  seams,  roughness,  and  insufficient 
care  in  tamping  the  ingredients  against  the  sides.  To  avoid 
leaving  any  impress  on  the  masonry,  the  wood  may  be  given  a 
fine  surface  or  may  be  coated  with  soap,  grease,  or  paraffine,  or 
covered  over  with  building  paper.  These  will  also  prevent  the 
concrete  from  sticking  to  the  wood.  A  sticky  oil  has  some- 
times been  applied  to  the  inner  face  of  forms,  and  clean  sand 
then  blown  over  it  from  a  bellows.  This  gives  a  uniform  surface 
which  appears  on  the  concrete  as  a  sand  finish.  A  rather  ex- 
pensive method  which  has  occasionally  been  used  on  important 
work,  is  to  cover  the  forms  with  expanded  metal  and  then  coat 
with  fine  plaster,  the  resulting  surface  being  so  smooth  as  to 
avoid  marks  of  any  kind  on  the  completed  exterior.  A  similar 
but  cheaper  way 'is  to  cover  the  forms  with  fine  clay  and  then 
overlay  the  clay  with  building  paper.  When  concrete  is  deposited 
against  the  boards,  unless  they  are  otherwise  covered,  they  should 
be  wet  with  a  hose  to  prevent  absorption  from  the  mixture  which 
would  result  in  too  rapid  or  uneven  drying.  When  exterior 
treatment  is  intended  after  the  forms  are  removed,  the  above 
precautions  are  unnecessary,  and  indeed,  a  poorer  grade  of 
lumber  can  be  used,  thereby  reducing  this  item  of  expense,  which 
will  to  some  extent  offset  the  extra  cost  of  after  treatment. 


CONCRETE  SURFACE  FINISH  127 

Since  it  is  difficult  to  avoid  joint  marks,  they  are  sometimes 
accentuated  by  fastening  small  triangular  strips  over  the  cracks 
between  the  planks,  leaving  horizontal  grooves  on  the  masonry 
somewhat  similar  to  stone  joints.  It  is  claimed  by  some  that 
such  markings  are  insincere  and  an  effort  at  imitation,  but  if 
used  wholly  to  efface  unsightly  lines,  they  would  seem  to  have 
a  sincere  and  truthful  purpose. 

Moulds  for  finer  work  have  been  made  of  wood,  metal,  sand 
and  plaster  of  Paris.  Artificial  stone  is  usually  cast  in  sand,  the 
cement  and  fine  crushed  stone  mixed  in  the  consistency  of  soft 
cream,  being  poured  into  the  sand  and  allowed  to  remain  there 
for  three  or  four  days.  The  excess  water  from  the  mixture 
easily  drains  off  through  the  sand  and  allows  the  stone  to  harden 
and  dry  uniformly  without  the  formation  of  surface  cracks. 

Need  of  Treatment. — There  appears  to  be  only  one  process  of 
building  concrete  in  which  an  after  treatment  of  the  exposed 
surface  is  unnecessary,  and  that  is  by  using  a  fairly  dry  and  lean 
mixture  on  the  face,  with  fine  aggregate.  With  concrete  of 
this  kind,  form  marks  do  not  appear  when  the  boards  are  re- 
moved. A  suitable  mixture  is  composed  of  cement,  sand  and 
fine-crushed  stone  in  the  proportions  by  volume  of  1,  1J  and 
4£,  the  stone  ranging  in  a  size  from  i  to  ^  in.  For  thin 
walls,  this  composition  is  used  alone,  but  on  thicker  ones,  it 
should  form  a  facing  about  1^  in.  thick  over  ordinary  concrete 
backing,  the  facing  mixture  being  placed  by  using  a  movable 
metal  shield,  or  by  any  of  the  other  approved  methods.  The  use 
of  a  dry  mixture  makes  a  wall  that  is  more  or  less  porous,  but  in 
Chicago  where  it  is  extensively  used  by  the  South  Park  Com- 
mission, after  a  trial  of  eight  years,  no  injury  from  frost  has 
been  found. 

Methods  of  Treatment. — The  surface  of  concrete  made  with  a 
wet  mixture,  and  enough  density  when  dry  to  be  impervious  to 
water,  almost  always  shows  imperfections  of  various  kinds, 
some  of  which  are  form  marks,  roughness,  cracks,  and  efflores- 
cence, and  these  can  be  removed  only  by  some  kind  of  after 
treatment.  After  several  years  of  careful  experiment  and 
investigation,  a  number  of  methods  of  treating  and  finishing 
concrete  surfaces  have  been  developed,  which  have  proved 
satisfactory.  These  methods  may  be  grouped  into  three  gen- 
eral classes,  (A)  Surface  Coating,  (B)  veneering,  and  (C)  surface 
removal.  These  may  be  further  subdivided  as  follows: 


128     ENGINEERING  OF  SHOPS  AND  FACTORIES 

(A)  Surface  Coating. 

(1)  Washing. 

(2)  Painting. 

(B)  Veneering. 

(3)  Brick,  stone  or  Tile  Facing. 

(4)  Plastering. 

(5)  Stucco  Finish. 

(C)  Surface  Removal.  *» 

(6)  Sand  Blasting. 

(7)  Tooling. 

(8)  Rubbing. 

(9)  Picking. 

(10)  Scrubbing. 

(11)  Pebble  Dashing. 

(12)  Acid  Etching. 

These  methods  are  described  somewhat  in  detail  in  the  following 
pages.  Before  proceeding  with  his  plans,  the  designer  should 
first  decide  upon  the  type  of  finish  which  he  prefers,  as  this  will 
affect  to  some  extent  the  actual  construction. 

SURFACE  COATING 

Washing  with  -cement  grout  and  painting,  are  the  usual 
methods  of  surface  coating,  though  both  of  them  are  carried  out 
in  many  ways,  differing  from  each  other  only  enough  to  allow 
patent  proprietors  to  establish  their  ownership. 

Washing  monolithic  surfaces  with  cement  or  lime  has  the 
merit  of  low  cost,  but  is  only  a  poor  substitute  for  something 
better,  as  it  is  not  stable.  Wherever  possible,  the  thin  grout 
should  be  applied  with  wooden  floats,  as  brushes  leave  streaks. 
A  cement  wash  is  made  by  mixing  three  parts  of  natural  or  Port- 
land cement  with  one  part  clean  sand  and  enough  water  to  make 
it  easily  applied.  The  mixture  should  be  as  thick  as  can  be 
worked  with  a  whitewash  brush,  and  the  whole  should  be  well 
stirred  before  using.  This  will  produce  a  gray  color,  the  shade 
depending  somewhat  on  the  brand  of  cement.  A  grout  of  cement 
and  plaster  of  Paris  is  also  used  and  may  be  similarly  applied. 
Brick  color  is  obtained  by  adding  10  per  cent,  by  weight  of  red 
iron  ore,  which  should  be  mixed  in  at  first.  By  increasing 
this  proportion  to  30  per  cent,  by  weight,  a  dark  red  color  re- 
sults. Venetian  red  cannot  be  recommended,  as  it  quickly 
fades.  If  a  white  surface  is  desired,  the  cement  wash  can  first 
be  applied  in  two  coats  and  whitewash  added  afterward.  These 
applications  will  adhere  better  when  applied  to  concrete  that  is 
green  or  moist. 


CONCRETE  SURFACE  FINISH  129 

A  good  whitewash  which  is  used  on  United  States  govern- 
ment lighthouses  may  be  made  by  first  slacking  a  bushel  of  lime 
with  boiling  water,  and  after  it  is  strained  adding  half  a 
bushel  of  salt  previously  dissolved  and  6  Ib.  of  ground  rice 
boiled  to  a  thin  jelly,  1  Ib.  of  powdered  Spanish  whiting,  and 
2  Ib.  of  dissolved  clear  glue.  It  should  be  thoroughly  stirred 
and  mixed,  and  applied  hot  with  a  whitewash  brush.  The  re- 
sulting surface  is  white  instead  of  the  gray  finish  from  cement 
wash. 

Whitewash  is  pure  white  lime  mixed  with  water,  and  it  adheres 
best  when  applied  hot,  but  is  easily  washed  off  by  rain  and  needs 
frequent  renewals.  The  wash  may  be  hardened  to  prevent 
cracking,  by  adding  to  each  bushel  of  lime,  1  Ib.  of  salt  and  2  Ib. 
of  zinc  sulphate.  It  may  be  tinted  by  adding  to  each  bushel 
of  lime,  4  to  6  Ib.  of  ochre  for  cream  color,  6  to  8  Ib.  of  raw 
umber  and  3  to  4  Ib.  of  lamp  black  for  buff  or  stone  color,  and  6 
to  8  Ib.  of  umber,  2  Ib.  of  Indian  red  and  2  Ib.  of  lamp  black  for 
fawn  color. 

Painting. — An  oil  paint  suitable  for  walls  is  made  by  mixing 
one  part  each  of  white  sand  and  quick  lime  with  two  parts  of 
wood  ashes,  the  whole  being  passed  through  a  fine  screen.  To 
this  mixture  as  a  base,  enough  raw  linseed  oil  may  be  added  to 
make  a  thin  paint  which  can  be  applied  with  a  brush.  If  color 
is  desired,  it  is  added  to  the  oil  before  mixing  with  the  base. 
.  Another  oil  paint  for  walls  is  made  by  mixing  100  Ib.  of  clean 
sand,  100  Ib.  of  white  lead,  20  quarts  of  raw  linseed  oil,  4  Ib. 
of  raw  umber,  1  Ib.  of  drier  and  1  pint  of  turpentine.  When 
mixed  to  the  proper  consistency,  it  can  be  applied  with  a  large 
brush. 

An  oil  wall  paint  known  as  Bay  State  Cement  Coating,  has  a 
cement  base  mixed  with  volatile  oil  which  evaporates.  It  con- 
tains no  lead,  glue  or  water  and  is  made  in  white  or  colors.  It 
can  be  applied  to  a  damp  surface,  will  not  absorb  water, 
dries  with  a  dull  finish,  and  may  be  washed  to  remove  dirt. 
It  is  made  only  in  liquid  form  ready  for  use  and  never  in  a 
paste. 

Concrete  surfaces  may  be  prepared  for  painting  by  coating 
them  when  dry  witt  a  mixture  containing  equal  parts  by  weight 
of  zinc  sulphate  and  water  applied  with  a  brush.  It  should  be 
allowed  to  dry  for  two  or  three  days,  after  which  paint  can  be 
applied  over  the  cement  the  same  as  over  ordinary  plaster. 
9  , 


130     ENGINEERING  OF  SHOPS  AND  FACTORIES 

VENEERING 

Brick  and  Stone  Veneering. — This  is  one  of  the  oldest  methods 
of  facing  concrete,  for  the  Romans  used  it  twenty  centuries  ago. 
Rubble  masonry  and  concrete  were  often  faced  with  tufa  and 
travertine  as  on  the  bridges  over  the  Tiber,  and  recent  excava- 
tions at  Pompeii  have  revealed  Concrete  walls  covered  with 
marble  slabs.  Many  of  the  finest  works  in  France  completed 
during  the  last  half  of  the  eighteenth  and  the  first  half  of  the 
nineteenth  centuries,  are  made  of  concrete  faced  with  stone. 
A  comparatively  recent  bridge  at  Soissons  is  similarly  faced  with 
separately  moulded  concrete  slabs.  In  America,  some  of  the 
finest  and  latest  manufacturing  buildings  have  exterior  con- 
crete frames  veneered  with  brick  or  previously  moulded  slabs  of 
concrete.  Good  effects  are  produced  by  a  judicious  use  of 
brick  in  different  colors  and  by  the  use  of  colored  tiles.  Decora- 
tive work  when  used,  should  be  concentrated  in  certain  places 
to  contrast  with  adjoining  unbroken  areas.  Colored  tiles  can 
be  cast  with  the  concrete  in  large  slabs  and  built  in  with  the 
walls,  or  a  space  may  be  paneled  out  of  the  walls  with  forms,  and 
the  tiles  set  in  afterward.  Concrete  blocks  or  artificial  stones 
are  used  more  for  solid  work  than  for  surface  facing,  and  are 
described  elsewhere. 

Plastering. — Plastering  on  concrete  walls  is  not  recommended, 
for  it  is  stable  only  when  moisture  cannot  reach  the  under  surface 
and  it  rarely  lasts  more  than  ten  to  fifteen  years  even  under 
favorable  conditions.  Before  applying  plaster,  the  concrete 
should  be  rough  and  clean,  without  scale  or  dust,  and  should 
be  wet  to  prevent  extracting  water  from  the  mortar  before  it 
hardens.  The  applied  material  should  be  pressed  and  worked 
well  against  the  under  surface  to  avoid  open  places  or  cavities 
which  would  quickly  break. 

A  finish  of  comparatively  recent  use,  known  as  Stonekote, 
is  a  mixture  of  Portland  cement  and  white  sand  or  white  quartz 
containing  no  lime.  In  hardness,  strength  and  durability  it 
is  nearly  equal  to  natural  stone  and  can  be  procured  in  several 
colors.  Three  coats  of  this  mixture  are  recommended  for  use 
on  sheathing  and  metal  lath,  with  100  Ib.  to  2^  yd.  of  surface, 
and  one  finish  coat  on  brick,  concrete,  or  concrete  blocks.  It 
can  be  applied  on  a  low-priced  concrete  wall,  making  a  rough 
cast  surface  of  the  desired  color,  which  may  be  waterproofed. 
Stonekote  is  slow  in  setting,  but  covers  all  joints  if  applied  by 


CONCRETE  SURFACE  FINISH  131 

first-class  workmen.     The   cost  per  square  yard  at  Chicago  is 
approximately  as  follows : 

Natural  color 28  cents  per  square  yard 

Colored  second  coat 32  cents  per  square  yard 

White  second  coat 36  cents  per  square  yard 

Rough  cast,  natural 37  cents  per  square  yard 

Rough  cast,  colored 38  cents  per  square  yard 

White  on  natural  base 40  cents  per  square  yard 

Light  colors  on  white  base 42  cents  per  square  yard 

Exterior  plaster  and  surface  finish  with  expanded  metal  will 
cost  from  75  to  90  cents  per  square  yard. 

SURFACE  REMOVAL 

Preparation  of  Surface. — To  produce  aesthetic  or  pleasing 
surface  effects,  a  special  preparation  must  be  made  of  the  surface 
material  before  placing  it,  and  the  details  of  such  preparation 
will  depend  upon  the  kind  of  surface  that  is  desired.  In  most 
cases  a  fine  aggregate  should  be  used  with  cement  sand  and 
fine  stone  in  the  proportion  by  volume  of  1,  1^  and  2£, 
with  stones  of  J-in.  to  £-in.  diameter.  This  mixture  should 
be  placed  at  the  same  time  as  the  coarse  backing  so  the  two  will 
unite,  and  to  avoid  hair  cracking,  it  should  not  be  richer  than 
given  above.  The  thickness  of  the  facing  surface  should  not  be 
less  than  twice  the  size  of  the  largest  aggregate  which  it  con- 
tains, and  never  less  than  1  in.  It  should  be  fairly  wet  when 
placed,  and  yet  firm  enough  so  the  large  stones  behind  it  will 
not  be  forced  through.  This  facing  when  1  in.  thick,  will  cost 
from  2  to  4  cents  per  square  foot,  not  including  any  after 
treatment. 

Coloring. — Coloring  can  be  affected  either  by  the  use  of  cer- 
tain kinds  of  sand  and  stone,  or  from  pigments.  No  kind  of 
fancy  aggregate  is  of  any  advantage  unless  the  surface  is  treated 
after  forms  are  removed,  for  they  all  have  the  same  leaden  gray 
shade  of  the  cement  in  which  they  are  enveloped.  Sand  can  be 
either  gray,  white  or  yellow  and  stone  is  obtainable  in  great 
variety  of  colors.  A  mixture  of  white  and  black  marble  or 
trap  rock  makes  a  pleasing  contrast,  while  brighter  effects  are 
obtained  from  colored  marbles  or  red  granite.  Other  hard 
material  such  as  broken  brick,  burnt  clay  or  tiles  may  be  added, 
and  all  of  these  can  be  crushed  to  any  desired  size,  and  colors 
mixed  to  suit  the  taste  of  the  designer  or  his  sense  of  beauty  and 
fitness. 


132     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Natural  coloring  is  preferable  to  artificial,  and  yet  when 
colored  aggregate  is  not  obtainable,  pigments  may  be  used. 
Mineral  pigments  only  are  suitable,  because  vegetable  colors 
are  not  permanent.  Red,  yellow,  blue  and  black  are  the  best. 
Some  common  pigments  with  their  approximate  cost  are  given 
in  Table  VIII. 

Buff  color  made  from  yellow  ochr'e  and  mineral  red  is  a  favorite, 
and  a  mixture  of  carbon  black  with  red  iron  ore  gives  a  dull  red, 
while  the  addition  of  lamp  black  to  the  last  produces  a  darker 
effect.  Lime  is  generally  used  for  whitening.  As  the  presence 
of  pigments  tends  to  lessen  the  strength  of  concrete,  the  amount 
of  pigment*  should  be  limited  to  5  per  cent,  by  weight  of  the 
cement,  or  5  Ib.  per  bag.  A  less  amount  than  this  will  give 
lighter  shades.  The  cement  aggregate  and  pigment  should  all 
be  mixed  together  dry,  and  it  should  be  observed  that  mortar 
when  wet  is  darker  than  when  it  is  dry. 

TABLE  VIII 


Approximate 

prices  per 

Pounds  color  re- 

Color desired 

Commercial 
names  of  colors 
for  use  in 

pound  in  100- 
Ib.  lots  for 
high-grade 

quired  for  each 
bag  of  cement  to 
secure 

colors 

cement 

Light 

Medium 

shade 

shade 

i 

1 

1 

Germantown 

10  cents 

\ 

1 

lampblack. 

Grays,  blue-black  ^ 

Carbon  black  

8  cents 

\ 

1 

and  black. 

Black  oxide  of 

6  cents 

2 
1 

2 

manganese. 

Blue  shade  

Ultramarine  blue.  . 

18  cents 

5 

10 

B  r  o  w  n  i  s  h-red  to 

Red  oxide  of  iron  .  . 

3  cents 

5 

10 

dull  brick  red. 

Bright  red  to  ver- 

Mineral Turkey  red  . 

15  cents 

5 

10 

milion. 

Red    sandstone    to 

Indian  red  

10  cents 

r 

10 

purplish-red. 

Brown     to      red- 

Metallic    brown 

4  cents 

5 

10 

dish-brown. 

(oxide). 

Buff    colonial  tint 

Yellow  ocher   . 

6  cents 

5 

10 

and  yellow. 

CONCRETE  SURFACE  FINISH  133 

Before  starting  construction,  it  is  worth  while  experimenting 
on  samples  to  get  the  color  effect  and  surface  finish  that  is  satis- 
fying, and  when  proportions  have  been  established,  they  should 
be  closely  adhered  to,  as  slight  variation  in  successive  batches 
of  concrete  may  give  shades  that  are  quite  noticeably  different. 
The  proportion  should,  therefore,  be  measured,  and  not  simply 
gauged  by  the  number  of  barrows.  Coloring  with  pigments 
will  usually  cost  from  \  to  2  cents  per  square  foot. 

Removal  of  Surface. — -Defects  and  irregularities  on  concrete 
surfaces  can  be  removed  by  the  sand  blast,  or  by  tooling,  rubbing, 
picking,  scrubbing  or  etching  with  acid.  The  objection  to  any 
kind  of  surface  removal  is  the  loss  of  the  outer  and  hardest  part 
of  the  mortar,  which  removal  may  allow  water  to  enter.  Rough- 
ening the  surface  by  any  of  the  processes  just  mentioned  causes 
the  building  to  more  easily  collect  grime  and  dust,  but  as  con- 
crete buildings  are  usually  of  a  smoky  gray,  such  dust  collection 
may  not  be  very  noticeable. 

Sand  Blasting. — This  method  is  economical  only  for  large 
areas.  It  cannot  be  undertaken  in  less  than  ten  days  or  two 
weeks  after  the  concrete  is  placed,  and  a  longer  time  of  about  a 
month  is  often  preferable.  For  this  reason,  it  is  suitable  for  the 
underside  of  girders  or  arches  where  forms  supporting  weight 
cannot  be  removed  in  less  than  thirty  days.  Air  should  have  a 
pressure  at  the  nozzle  of  50  to  80  Ib.  per  square  inch,  and  the 
nozzle  should  not  be  larger  than  J  to  \  in.  diameter,  for  if  greater, 
the  jet  of  sand  cannot  be  concentrated  on  small  defects.  Sand 
should  be  clean  and  hard  and  of  a  size  to  pass  a  No.  12  screen 
for  J-in.  nozzle,  and  a  No.  8  screen  for  J-in.  nozzle.  The  cutting 
action  of  the  sand  removes  the  surface  film  of  cement  at  a  cost  of 
about  3  cents  per  square  foot.  Work  can  usually  be  done  by,  or 
with  apparatus  from,  some  company  of  building  cleaners. 

Tooling. — -Tooling,  to  remove  about  TV  in.  from  the  surface 
may  be  done  either  by  hand  or  pneumatic  process,  hand  work 
being  cheaper  for  small  jobs,  and  especially  for  low  walls  where 
scaffolding  is  not  needed.  For  large  areas,  high  above  ground, 
air  tools  will  probably  be  cheaper  than  hand  work  by  30  to  50 
per  cent.  The  concrete  should  be  two  to  three  weeks  old  and 
the  best  results  are  usually  obtained  from  a  fine  aggregate.  If 
large  stones  lie  near  the  surface,  the  concrete  should  be  at  least 
two  months  old,  to  prevent  stones  from  being  knocked  out  by 
the  tools  instead  of  being  cut.  One  laborer  will  dress  from  50 


134     ENGINEERING  OF  SHOPS  AND  FACTORIES 

to  100  sq.  ft.  per  day  when  concrete  has  not  been  placed  longer 
than  two  to  three  weeks,  the  cost  for  hand  work  being  from 
If  to  3£'  cents  per  square  foot,  not  including  staging,  or  as 
low  as  1J  cents  per  square  foot  when  labor  wages  do  not 
exceed  $1.50  per  day.  Bush  hammering  can  be  done  quite  as 
well  by  common  as  by  skilled  labor,  though  in  some  cases,  the 
better  grade  of  labor  has  been  usett  in  accordance  with  regula- 


FIG.  72. 


tions  of  labor  unions  and  frequently  on  government  work. 
Tooling  such  as  generally  used  on  Bedford  or  similar  stone  can 
be  done  to  the  best  advantage  when  the  concrete  has  a  fine 
mortar  face  and  has  thoroughly  hardened.  In  this  case  experi- 
enced stone  cutters  are  needed.  Machine  work  with  pneu- 
matic tools  can  be  done  at  the  rate  of  300  to  600  super- 
ficial feet  per  man  per  day,  at  a  cost  on  large  areas  of  1^  to 
3  cents  per  square  foot,  with  labor  wages  at  $2  per  day. 
Those  who  have  done  this  kind  of  work  extensively,  recommend 
the  more  liberal  allowance  of  3  to  4  cents  per  square  foot  for 
green  surfaces  and  5  to  10  cents  per  square  foot  for  hard  surfaces. 
Some  tooling  effects  are  shown  in  Fig.  72. 


CONCRETE  SURFACE  FINISH  1-35 

Rubbing. — In  this  method,  the  surface  is  rubbed  or  ground 
with  a  brick,  a  block  of  sandstone  or  carborundum,  after  the 
forms  have  been  removed,  which  should  be  between  six  and 
forty-eight  hours  after  placing.  To  facilitate  grinding,  a  wash 
of  cement  and  sand  mixed  in  the  proportion  of  1  to  2,  should  be 
used  between  the  wall  and  the  grinding  stone.  A  s  lather  forms 
it  may  be  washed  off,  and  the  grinding  process  continued  after 
applying  more  cement  and  sand.  When  rubbing  is  done  with 
carborundum,  a  No.  16  stone  is  most  appropriate  for  the  first 
application,  but  the  finishing  should  be  done  with  a  No.  30. 
This  method  is  most  suitable  for  fine  mortar  facing  and  when 
soft  stone  such  as  marble  is  used  in  the  aggregate,  the  process 
being  similar  to  that  used  in  finishing  a  Terrazza  floor.  The 
cost  should  not  exceed  1^  to  2  cents  per  square  foot,  or  4 
cents,  with  carborundum.  A  variation  of  this  method  is  to 
cut  the  surface  with  sand  rubbed  on  with  a  plasterer's  float, 
using  plenty  of  water,  in  which  case  a  laborer  can  wash  and 
clean  100  sq.  ft.  per  hour. 

Picking. — This  work  can  be  done  either  by  hand  or  pneumatic 
tools.  Within  three  or  four  days  after  the  concrete  is  placed  a 
laborer  can  do  four  times  as  great  an  area  as  he  could  when  con- 
crete is  only  two  weeks  old.  The  costs  are,  therefore,  as  follows: 

Picking  concrete 6  to  24  hours  old 1  cent  per  square  foot. 

Picking  concrete 2  days  old 2  to  3  cents  per  square  foot. 

Picking  makes  a  rougher  and  coarser  surface  when  green  than 
when  dry,  and  experience  shows  that  one  man  with  air  tools  can 
dress  400  to  500  sq.  ft.  per  day. 

Scrubbing. — In  this  method,  while  the  concrete  is  still  green 
the  surface  is  washed  with  stiff  brushes  to  remove  enough  of  the 
cement  that  the  stone  and  aggregate  may  be  plainly  exposed. 
Aggregate  in  the  facing  mixture,  which  should  be  at  least  1 
in.  thick,  may  consist  of  pebbles,  fine-crushed  granite,  trap 
rock,  broken  brick,  or  a  mixture  of  several  kinds  of  stone  and 
these  materials  can  be  plainly  exposed  when  a  little  of  the  cement 
is  washed  away  (Figs.  73-78).  The  rate  at  which  work  can 
be  done  will  depend  largely  on  the  hardness  which  the  concrete 
has  attained.  For  different  climatic  conditions,  the  time  of 
form  removal  should  be  as  follows : 

In  hot  weather,  remove  forms  in 24  hours. 

In  cooler  weather,  remove  forms  in 2  to  3  days. 

In  cold  and  wet  weather,  remove  forms  in 6  to  7  days. 


136     ENGINEERING  OF  SHOPS  AND  FACTORIES 


FIG.  73. — Scrubbed  and  etched  surface  of  1-3  fine  sand  mortar. 


FIG.  74. — Scrubbed  and  etched  surface  of  1-3  coarse  sand  mortar. 


FIG.  75. — Scrubbed  and  etched  surface  of  1-3  small  pebble  mixture. 


CONCRETE  SURFACE  FINISH 


137 


FIG.  76. — Scrubbed  and  etched  surface  of  1-2 1  mixture  of  fine  granite 

screenings. 


FIG.   77. — Scrubbed  and  etched  surface  of   1-2}   mixture  coarse  granite 

screenings. 


FIG.  78. — Scrubbed  and  etched  surface  of  1-2}  mixture  of  coarse  pebbles. 


138     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  above  rule  applies  only  to  face  work,  where  the  forms  sup- 
port no  dead  load.  Under  beams  or  floors  they  must  usually 
remain  in  place  for  at  least  a  month.  When  this  work  is  done 
with  cement  at  the  right  degree  of  hardness,  a  man  can  wash  out 
enough  of  the  surface  with  three  or  four  passages  of  an  ordinary 
kitchen  scrubbing  brush.  The  work  must  not  be  undertaken 
too  soon,  for  stones  might  then  berdislocated  leaving  unsightly 
holes,  and  on  the  other  hand,  if  delayed  too  long  the  work  is 
slower  and  more  expensive.  In  some  cases  it  can  be  done  in 
eight  to  ten  hours  after  the  concrete  is  placed,  but.  when  delayed 
too  long,  wire  brushes  may  be  needed. 

By  this  method  quite  a  variety  of  effects  can  be  produced  by 
using  stone  of  different  size  and  color,  and  the  result  is  a  truthful 
expression  of  concrete  construction,  exhibiting  as  it  does,  the 
very  make-up  of  the  material.  The  effect  "is  improved  if,  after 
scrubbing,  the  surface  is  washed  with  hydrochloric  acid  mixed 
with  five  times  its  volume  of  water.  This  cleans  the  aggregate 
and  brightens  the  color,  but  the  face  must  afterward  be  thor- 
oughly washed  with  a  hose  to  avoid  future  discoloration.  Any 
kind  of  limestone  or  marble  which  would  be  attacked  by  acid 
cannot  be  used  when  etching  is  intended.  Forms  should  be 
taken  down  only  fast  enough  to  keep  an  hour's  work  ahead  of 
the  scrubbers,  and  on  vertical  surfaces  this  can  be  arranged  by 
setting  the  studs  out  from  the  forms  on  blocks,  which  are  easily 
knocked  out  as  needed,  allowing  the  boards  to  be  taken  away. 
When  done  at  the  right  time,  a  man  can  scrub  100  sq.  ft.  per 
hour,  though  it  may  take  him  two  to  five  times  as  long  if  the 
work  is  delayed  until  the  cement  is  hard. 

An  effect  somewhat  similar  to  that  described  above,  can  be 
obtained  by  plastering  the  inside  face  of  the  outer  form  boards 
with  stiff  clay  |  in.  thick,  and  embedding  in  the  clay  a  layer 
of  pebbles  of  random  size,  laid  close  together.  Concrete  is  then 
poured  in  and  tamped  against  this  facing.  After  twenty-four 
hours,  the  forms  are  removed  and  the  clay  washed  away  with  a 
brush  and  hose,  leaving  the  pebbles  exposed,  which  are  now  a 
part  of  the  concrete  wall. 

Acid  Etching. — The  exterior  film  of  cement  on  concrete  walls 
may  also  be  removed  wholly  by  acid  etching,  but  the  acid  must 
be  used  with  care,  for  if  not  thoroughly  washed  off  afterward, 
discoloration  will  develop.  When  this  process  is  intended,  the 
aggregate  must  contain  no  limestone  or  marble,  as  these  would 


CONCRETE  SURFACE  FINISH  139 

be  attacked  and  decomposed  by  acid.  Either  hydrochloric  or 
sulphuric  acid  may  be  used,  though  the  former  is  usually  pre- 
ferred, and  the  strength  will  depend  upon  the  age  of  the  com- 
position. When  concrete  is  only  two  days  old,  the  acid  may  be 
diluted  with  five  or  six  times  its  volume  of  water,  but  when  two 
weeks  old,  the  acid  should  be  twice  as  strong.  At  the  end  of 
thirty  days,  the  mixture  should  combine  one  part  of  acid  with 
two  of  water,  and  the  liquid  may  be  allowed  to  remain  on  the 
surface  for  thirty  minutes  before  washing  it  away.  Concrete 
made  with  white  sand  and  fine  crushed  stone,  after  being  etched 
in  this  way  to  remove  the  outer  film  of  cement,  gives  the  appear- 
ance of  fine  finished  white  stone. 


CHAPTER  X 

COST  OF  REINFORCED  CONCRETE    BUILDINGS1 

The  most  recent  report  of  specific'costs  of  reinforced  concrete 
factory  buildings  is  that  presented  at  the  convention  of  the 
National  Association  of  Cement  Users  in  March,  1912.  These 
costs  in  detail  are  given  in  Table  IX. 

From  this  table  it  appears  that  the  average  cost  of  single- 
story  buildings  with  saw-tooth  roof  is  $1.77  per  square  foot  of 
floor  and  8^  cents  per  cubic  foot  of  contents,  while  the  average 
cost  of  buildings  with  more  than  one  story  is  $1.12  per  square 
foot  or  8.7  cents  per  cubic  foot  of  contents.  These  figures  are  on 
the  complete  building  with  plumbing,  but  they  do  not  include 
heating,  lighting,  sprinkler  system,  elevators  or  power  equip- 
ment. The  square  foot  prices  were  obtained  by  dividing  the 
total  cost  of  the  building  by  the  aggregate  floor  area  including 
the  basement,  but  not  including  the  roof. 

Another  report  on  the  cost  of  reinforced  concrete  buildings 
read  in  1909  before  the  National  Association  of  Cement  Users 
gives  the  specific  costs  of  a  number  of  buildings,  which  are 
shown  in  Table  X. 

From  this  table  it  appears  that  the  average  cost  of  twenty-one 
buildings  was  $1.72  per  square  foot  of  floor  area,  and  13.8  cents 
per  cubic  foot  of  contents.  This  table  is  followed  by  a  detailed 
cost  analysis  of  forms  and  concrete  in  place,  which  is  repro- 
duced in  Table  XI. 

It  appears,  therefore,  that  the  average  cost  of  forms  per  square 
foot,  is  for  columns  13  cents,  beam  floors  11.6  cents,  slab  floors 
11.1  cents,  slabs  only  between  steel  beams  9.5  cents,  walls  above 
ground  12.8  cents,  foundations  10.3  cents,  and  footings  9.3  cents. 

A  subdivision  giving  the  percentage  cost  of  concrete,  steel, 
labor  and  forms  is  as  follows: 

Concrete,  costs  19  per  cent,  of  the  total 

Steel,         costs  17  per  cent,  of  the  total 

Labor,       costs  31  per  cent,  of  the  total 

Forms,       costs  33  per  cent,  of  the  total 

Total 100  per  cent. 

1  H.  G.  Tyrrell,  in  Engineering  Magazine,  June,  1912. 

140 


COST  OF  REINFORCED  CONCRETE  BUILDINGS  141 


£  * 

l>               CO                                              rH 

O5   t^-t^C^t^OI^Ot^-t^ 

OOOi—  lOrHOrHOO 

^^     rH 

03                               U 

& 

^          £* 

£*•    00    O5    ^D    O^    ^O    O5    iO    *O    *O 

rH     O^     ^D     ^O     ^2     *O     t^»     Is*     rH     00 

CO     Tf 

4  r 

rH 

H< 

olUc 

<M(NlM(N(MrH(N<N(NrH 

xxxxxxxxxx 

OOOt^COfNCOCOOOOCO 

6X16-8 

o        t^        oo                  05 

rH               rH               rH                                    rH 

1    M       :           U 

• 

<a 
'o 

jO   -O       •       •   42   -O                      •   ,Q 

«  rS    :    :  -2  ^           :  js 

IJj       OQ          .          .       OQ       0}                              .50 

llfflllljl 

1  1*22  1  1^2  I 

WfflSfoWWcocoSW 

2 

"a: 

+J 

||| 

iOl>»»OiO<NOOQ       -iO*C 

0 

~S        ^ 
•g  *S  g  'J 

co          CO  CO                   •      •   CO 
<NCO(N<NTt<CO               -^(M 

00 

w     »  <~ 

|       | 

"—       CO 

O     O 

ll 

•^fC^T^lOC^tNrHl—I^O 

rH 

IN 

rH 

CD 
69    -fS 

OO          •     O     O     CO     rH     O     r-  1     O 

xx   :xxxxxxx 

OO5         -OlOCOrHOCOOi 
rH                                        C^    -H             rH 

1  
100X256 

•         .         .                 .        .        .                 .        . 

. 

& 

a    •    •      -J    •    :  -i    • 

o     •     •        rs     '  _  i    o     ' 

^^    •  a  g    :^rddcD' 

W    '3         '    "3                   •    _2      02      OD      00 

§  a    :"2I'fr1  §11 

i-2  •  5  1  1  S  1  1  1 

•5+3     •   3   3   Q   5   S   5   5 

|2     ^           •t>k5l=l3L>-hH-^-ri 

^O        -r^WpH^r^COCO 

Storehouse  . 
Storehouse  . 

142     ENGINEERING  OF  SHOPS  AND  FACTORIES 

TABLE  X.— COST  OF  CONCRETE  BUILDINGS 


Type 

Place 

Total 
cost  of 
bldg. 

Volume 
in  cubic 
feet 

Floor 
area,  sq. 
ft. 

Costs 

Cu.  ft. 

Sq.  ft. 

Store  
Hospital  
Office  
Cold  store  
Factory  
Factory  
Storehouse  
Factory  
Office  
Factory  
Factory  
Factory  
Office  . 

Nashua  
Buffalo  
Everett 

$141,735 
60,800 
61,646 
200,051 
19,292 
141,529 
76,796 
91,377 
136,880 
133,064 
75,604 
23,332 
181,194 
12,774 
44,652 
39,830 
10,436 
19,993 
6,757 
3,625 
20,076 

1,714,400 
703,692 
496,780 
1,535,000 
212,400 
1,329,868 
1,140,000 
1,380,500 
693,840 
105,600 
1,211,364 
180,000 
1,365,800 
112,440 
746,674 
312,000 
156,198 
149,250 
44,265 
9,734 
59,991 

168,696 
57,654 
39,840 
154,000 
15,000 
106,000 
146,000 
90,240 
56,552 
8,800 
75,604 
16,394 
90,474 
7,519 
49,546 
24,960 
10,806 
19,208 
2,982 
657 
5,243 

$.0827 
.0865 
.124 
.13 
.091 
.107 
.0685 
.067 
.197 
.124 
.0625 
.129 
.133 
.114 
.060 
.127 
.085 
.134 
.153 
.373 
.333 

$.84 
.05 
.545 
.30 
.28 
.335 
.575 
1.01 
2.42 
1.485 
1.01 
1.42 
2.00 
1.70 
.902 
1.60 
1.23 
1.04 
2.26 
5.45 
3.82 

Boston 

Chelsea  
Cambridge  
Saco  
Providence  
Jacksonville  
Cambridge  
Cambridge  
Cambridge  
Portland  
Greenfield  
Southbridge  
Attleboro  

Factory  
Factory  
Factory  
Garage  
Filter  

Brookline  
Lawrence  
Weston  
Milton  
Lawrence  

Fire  station  
Observatory  
Filter  

Average  

.138 

1.72 

This  analysis  assumes  that  materials  can  be  delivered  at  the 
site  on  cars,  and  that  form  lumber  can  be  used  twice.  As  two- 
thirds  of  the  total  cost  is  for  labor  and  forms,  and  one-third  for 
the  forms  alone,  it  is  economical  where  time  will  permit,  to  use 
forms  more  than  twice,  or  as  often  as  the  lumber  will  last.  Repe- 
tition and  duplication  of  forms  are,  in  fact,  the  greatest  factors 
in  cost  reduction,  and  the  design  should  be  so  made  that  this  is 
possible.  The  average  cost  of  forms  obtained  from  a  different 
set  of  records  from  those  given  above,  is,  for  floors  with  beams, 
girders  and  slabs,  10  cents  per  square  foot,  and  for  flat  slab 
floors  without  beams  7  cents  per  square  foot.  The  correspond- 
ing cost  of  column  forms  is  13  cents  per  square  foot.  The  cost 
of  bending  and  placing  reinforcing  steel,  including  wire  mesh  in 
slabs,  varies  from  $5  to  $17  per  ton,  the  average  being  about 
$10  per  ton. 

A  reinforced  concrete  building  designed  by  the  writer,  55  ft. 
wide  and  88  ft.  long  with  seven  stories  and  basement  and  500,000 
cu.  ft.  of  contents,  cost  $1.15  per  square  foot  of  floor,  or  9.1  cents 
per  cubic  foot  of  contents.  The  floors  were  proportioned  for 


COST  OF  REINFORCED  CONCRETE  BUILDINGS  143 


i 

o  *o 

»O    O5     rH 

—    10    0 

O5    OS 
CO    CO 

0 

CO    CO 

CO    CO    CO 

CO    CO 

H 

d 

£3 

o  o 

CO     rH     rH 

o  o  o 

§§ 

! 

S 

be    • 

c 

d 

~o 

a 

0    0 

rH     CO     CO 

rH      O 

o  o 

<+H 
O 

1 

2 

o 

Q)        Q) 

81 

33 

0   CD 

O   00   CO 
l>-   CO   l> 

000 

CO    t^ 

CO  l> 

d 

o 
o 

49 

d 

0> 

a 

^§ 

O    rH 

co  oo  co 

05    CO    l> 

O     rH     O 

0     rH 

go* 

^-> 

Q 

o 

1 

2  S 

^ 

10   ^ 

CO    CO 

§rH     T—  1 
0    0 

rH     O 

o  o 

il 

CO    rH 

S3 

l>    CO    O 

Oi    ^^    O^ 

CO    iO 

t^»     ^t^ 

0    0 

o 

•8 

1 

C^S 

rH     — 

rH     IO    00 

rH     OJ     CO 
rH     O     rH 

co  co 

2  § 

-4-J 

1 

H 

1 

rH     CO 

8§ 

CO    CO    CO 

CO    <N 

»1 

0) 

,3 

CO    »O 

00    CO    CO 

CO    "^ 

s 

a 

o  o 

o  o  o 

o  o 

e 

^ 

49 

6 

,0 

CO    O 

oo  i> 

o  o 

rH    rH    1C 

l>-    CO    00 

o  o  o 

CO    iO 

:  s 

:  o 

CQ      ^>^ 

o 

o  'S     • 

*r£     jfi 

a  "g 

o  o    : 

1  If 

6  fS 

111 

1  1 

144     ENGINEERING  OF  SHOPS  AND  FACTORIES 


a  total  load  of  200  ib.  per  square  foot,  and  the  prices  given  above 
include  excavation,  foundations,  walls,  columns,  floors,  framing, 
roofing,  windows,  doors  and  stairs,  but  do  not  include  plumbing, 
elevators,  heating,  lighting,  or  partitions. 

Concrete  factory  buildings  from  one  to  five  stories  in  height 
and  about  50  ft.  wide,  will  .have  minimum  costs  about  as  follows: 


Cost  per  square 
foot  of  floor  area 

Cost  in  cents  per 

cubic  foot  of  contents 

K 

3   4  and  5  stories  

$1.00  to  $1.10 

7  5  to    85 

2  stories               

1.05  to    1  15 

8  0  to    90 

Istorv 

1  10  to    1  20 

8  5  to  10  0 

These  prices  do  not  include  partitions,  plumbing,  heating, 
lighting  or  elevators.  In  the  South  or  in  country  districts  where 
labor  is  cheaper,  the  unit  costs  may  occasionally  be  10  to  15  per 
cent.  less.  But  when  buildings  are  erected  by  contractors  who 
are  only  occasionally  employed  on  such  work,  the  cost  is  likely 
to  exceed  the  minimum  prices  given  above,  and  amount  to  $1.30 
per  square  foot  for  buildings  of  three  stories  or  more,  to  $1.60 
per  square  foot  for  those  with  only  single  stories.  Concrete 
framing,  including  slabs,  beams  and  columns  only,  without  wralls, 
costs  from  45  to  65  cents  per  square  foot  of  floor  area. 

The  cost  of  reinforced  concrete  buildings  from  numerous 
designs  and  estimates  made  by  the  writer  (see  Tyrrell' s  Mill 
Buildings)  varies  from  6  to  12  cents  per  cubic  foot  for  factories 
and  warehouses,  and  from  10  to  16  cents  per  cubic  foot  for  stores 
and  loft  buildings.  These  are  based  upon  the  use  of  complete 
concrete  frames  and  exterior  curtain  walls,  without  power,  heat, 
light,  elevators  or  interior  finish.  Buildings  with  concrete  slabs 
and  2-in.  cement  finish,  costing  $1.25  per  square  foot,  would 
with  cement  finish  on  2-in.  cinder  concrete,  cost  about  $1.30  per 
square  foot,  and  $1.35  per  sq.  ft.  with  J  maple  on  2-in.  cinder 
concrete,  with  a  concrete  floor  slab  in  each  case.  (See  Con- 
crete Floors.) 

A  two-story  reinforced  concrete  factory  building  100  ft.  square, 
at  Walkerville,  Ontario,  with  6-in.  curtain  walls,  and  columns 
16  ft.  apart  in  both  directions,  cost  complete,  including  concrete, 
rods  and  forms,  $19.88  per  cubic  yard  of  concrete  in  place. 


COST  OF  REINFORCED  CONCRETE  BUILDINGS  145 


Some  contractors  use  the  following  method  of  estimating  the 
cost  per  cubic  yard  of  all  material  in  place.  First  find  the  cost, 
delivered  at  the  site,  of  the  cement,  sand  and  stone  required 
for  a  cubic  yard  of  concrete,  and  to  this  add  $5  per  yard  for  the 
reinforcing  metal.  The  sum  of  these  two  costs  is  assumed  to 
represent  one-half  of  the  total  per  cubic  yard  of  the  materials 
in  place.  The  labor  of  mixing  and  placing  the  concrete  and  of 
placing  the  steel  will  add  one-third  to  the  above  sum,  and  the 
material  and  labor  on  forms  will  be  two-thirds  more.  The 
resulting  cost  does  not  include  contractor's  profit  or  plant  de- 
preciation. General  expense  and  cleaning  -up  after  completion 
may  be  $1  to  $2  per  cubic  yard  additional. 

A  considerable  saving  in  the  cost  of  reinforced  concrete  build- 
ings can  be  affected  by  omitting  the  floor  slabs,  and  using  a 
frame  of  columns  and  girders  only,  with  a  double  course  of  boards 
supported  on  reinforced  concrete 
beams  (Fig.  79) .  As  previously 
noted,  a  four-story  office  build- 
ing of  this  kind  at  Fore  River, 
Mass.,  a  large  part  of  the  curtain 


' —  Cinder  Concrete 


FIG.  79. — Reinforced  concrete  beams  with  wood  floor. 

walls  being  glass,  cost  with  the  foundations,  walls,  roof  and 
floors,  only  63  cents  per  square  foot  of  floor  area,  or  4£  cents 
per  cubic  foot  of  contents.  Including  lighting,  heating,  toilets 
and  partitions  the  cost  was  $1.30  per  square  foot  of  floor,  or 
9.2  cents  per  cubic  foot.  Another  similar  five-story  building  in 
the  same  state,  50  by  300,  cost  only  7.6  cents  per  cubic  foot. 

Economy  often  results  also  from  the  use  of  separately  moulded 
floor  members,  a  good  example  being  the  cold  storage  warehouse 
at  Syracuse,  previously  described.  The  building  was  six  sto- 
ries high,  and  78  feet  square,  and  concrete  floors  of  the  Watson 
system  (Fig.  65)  were  supported  by  a  frame  of  steel  beams  and 
columns.  The  floors  alone  cost  20.5  cents  per  square  foot,  and 
the  steel  framing  and  fireproofing  21.5  cents  additional,  or  a 
total  of  42  cents  per  square  foot  of  floor  area,  and  4  cents  per 
10 


146     ENGINEERING  OF  SHOPS  AND  FACTORIES 

cubic  foot  of  volume  for  both  floor  and  frame.  Including  the 
gravel  roof,  curtain  walls  and  stairs,  the  cost  was  61  cents  per 
square  foot,  or  5.7  cents  per  cubic  foot,  the  granolithic  floor 
finish,  and  wall  plastering  not  being  included.  In  determining 
these  unit  prices,  the  area  of  six  floors  and  basement,  was  taken 
inside  of  the  exterior  walls. 

Much  of  the  published  information  in  reference  to  the  cost  of 
concrete  work  is  based  upon  the  records  of  well-organized  build- 
ing companies  who  are  equipped  to  do  such  work  in  the  most 
economical  manner.  Other  builders  with  less  'facilities  should 
therefore  be  liberal  in  their  estimates.  Some  contractors  when 
estimating  use  a  cost  unit  for  reinforced  concrete  of  $1  per  cubic 
foot  or  $27  per  cubic  yard  for  all  material  in  place,  which  is  no 
doubt  large  enough  for  even  inexperienced  builders.  (For  other 
costs,  see  "  Reinforced  Concrete  Floors/') 


CHAPTER  XI 

COMPARATIVE  COST  OF  WOOD,  REINFORCED  CONCRETE  AND 
STEEL  BUILDINGS 

Where  wooden  buildings  are  referred  to  in  the  following 
comparisons,  only  mill  construction  of  the  slow  burning  type  is 
considered,  for  nearly  all  modern  industrial  enterprises  are 
housed  in  buildings  that  are  to  some  extent  fireproof.  The 
question  may  reasonably  be  asked  here,  what  constitutes  a  fireproof 
building?  Nothing  is  more  fireproof  than  a  furnace  and  yet  the 
decomposition  of  its  contents  by  fire  is  its  chief  use.  These 
buildings  must,  therefore,  not  only  be  made  of  non-inflammable 
material  but  they  must  be  so  arranged  that  fire  when  started 
can  be  confined  to  one  room  or  to  the  smallest  possible  space. 
With  this  object  in  view,  they  should  be  equipped  with  self- 
closing  metal  doors,  and  windows  with  wire  glass  or  metal 
shutters.  They  should  have  automatic  fire  alarms,  and  above 
all  an  adequate  sprinkler  system.  Steel  framing  must  be  en- 
closed and  protected  with  some  material  such  as  brick,  tile,  terra- 
cotta or  concrete.  Under  these  conditions  with  insurance  on 
the  contents,  a  manufacturing  enterprise  is  reasonably  safe. 

Building  types  arranged  in  order  of  their  relative  first  cost  are 
as  follows : 

A.  Complete  steel  frame,  fireproofed,  with  curtain  walls  and 
plank  floor. 

B.  Interior  steel  frame,  fireproofed,  with  solid  brick  walls  and 
plank  floor. 

C.  Complete  steel  frame,  fireproofed,  with   curtain  walls  and 
reinforced  concrete  floors. 

D.  Interior  steel  frame,  fireproofed,  with  solid  brick  walls  and 
reinforced  concrete  floors. 

E.  Entire  reinforced  concrete  building. 

F.  Part  interior  steel  frame,  not  fireproofed,  with  solid  brick 
walls  and  wood  mill  floors. 

G.  Entire  wood  mill  construction. 

147 


148     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  first  cost  is,  however,  not  always  the  governing  considera- 
tion, for  in  these  times  of  large  enterprises,  any  reasonable 
investment  is  permissible  which  will  result  in  ultimate  economy, 
when  the  expenses  of  maintenance,  depreciation,  interest  and 
insurance  are  considered.  The  selection  of  a  building  type  is, 
indeed,  a  choice  of  the  most  profitable  investment. 

The  annual  depreciation  of  w6od  mill  buildings  is  usually 
assumed  at  1  to  1^  per  cent,  of  their  first  cost,  and  the  corre- 
sponding depreciation  of  concrete  buildings  would  probably  not 
exceed  half  of  1  per  cent.,  though  on  this  subject  there  is  little 
reliable  information  as  the  type  is  comparatively  new.  Oscilla- 
tion and  vibration  in  building  frames  of  wood  and  steel,  cause  a 
further  loss  in  machinery  repairs  and  increased  power,  which  is 
variously  estimated  at  1/2  to  1  per  cent,  of  their  first  cost,  and 
this  loss  is  avoided  by  the  use  of  rigid  framing  such  as  concrete. 
Fireproof  types  have  a  slight  advantage  also  over  wood  construc- 
tion in  the  matter  of  sanitation  and  light,  for  more  wall  area  is 
available  for  windows,  and  rats,  mice  and  other  vermin  have 
less  chance  to  collect  and  live. 

In  comparing  the  first  cost  of  buildings  in  wood  mill  construc- 
tion and  in  reinforced  concrete,  it  will  be  found  that  their  relative 
cost  varies  with  the  location,  size  of  building  and  the  floor  loads 
to  be  sustained.  In  the  Southern  States,  or  other  regions  where 
timber  is  abundant  and  cheap,  wood  construction  will  often 
cost  25  to  30  per  cent,  less  than  reinforced  concrete,  while  in 
districts  where  wood  is  scarce,  the  two  types  may  be  nearly 
equal. 

The  comparison  depends  also  on  the  size  of  the  building,  for 
large  ones  have  often  been  found  to  cost  about  the  same  in  either 
material,  and  small  ones  are  sometimes  more  expensive  by  30, 
40  or  50  per  cent,  in  reinforced  concrete  than  in  wood.  The 
required  floor  capacity  also  affects  the  comparison.  Light  loads 
with  long  spans  are  cheaper  in  wood  mill  construction  than  in 
reinforced  concrete,  the  cost  of  the  two  types  being  nearly  equal 
in  large  buildings  with  200-lb.  imposed  loads  per  square  foot, 
and  column  spacing  of  18  to  20  ft.  With  loads  of  300  to  500  Ib. 
per  square  foot,  concrete  becomes  the  cheaper,  and  the  saving 
increases  rapidly  with  greater  loads  of  1000  to  1200  Ib.  per 
square  foot. 

A  concrete  building  designed  by  the  writer  and  containing 
about  500,000  cu.  ft.,  was  found  to  cost  17  per  cent,  more  than 


WOOD,  CONCRETE  AND  STEEL  BUILDINGS     149 

one  in  wood  mill  construction,  and  about  the  same  as  a  building 
with  complete  interior  fireproofed  steel  frame,  solid  walls  and 
wood  floors.  It  was  in  Ohio,  and  the  total  floor  load,  including 
both  live  and  dead,  was  200  Ib.  per  square  foot.  (See  Tyrrell's 
Mill  Buildings,  p.  62.) 

As  a  general  rule,  therefore,  it  will  be  found  that  reinforced 
concrete  in  the  Northern  States,  costs  about  the  same  as  wood 
for  large  buildings,  worth  $250,000  or  more,  with  heavy  loads. 
Those  worth  $25,000  to  $100,000  will  usually  cost  10  to  20  per 
cent,  more  in  concrete  than  in  wood,  and  small  structures,  espe- 
cially for  light  loads,  may  be  cheaper  in  wood  by  30,  40,  or 
even  50  per  cent. 

The  following  table  gives  a  miscellaneous  lot  of  bids  and  esti- 
mates on  manufacturing  buildings,  with  comparative  costs  in 
wood  mill  construction  and  in  reinforced  concrete.  It  will  be 
seen  that  the  costs  in  most  cases  are  from  1  to  27  per  cent,  higher 
in  concrete  than  in  wood,  though  two  of  them  are  cheaper  in 
concrete. 


TABLE    XII.— COMPARATIVE    COST    OF    WOOD    MILL    CONSTRUCTION    AND 
REINFORCED  CONCRETE  BUILDINGS 


Kind 

Place 

Size 
ft. 

Stories 

Load 
Ibs. 

Cost  of 
wood 
bldg. 

Cost  of 
concrete 
bldg. 

Concrete 
more  or  less 
than  wood 
% 

Factory.  . 

Detroit  . 

3 

300 

$28  200 

$28  500 

Bid 

Factory.  .  .  . 
Factory.  . 

Jersey  City.  . 
Grand  Rapids 

60X140 

5 

200 

52,000 
85  300 

56,000 
86000 

7.1  more 

Bid 
Bid 

Factory  
Factory.  .  .  . 
Warehouse 
Warehouse 
Warehouse 
Warehouse 
Press  bldg.. 

Fall  River.  .  . 
Manchester. 
Boston  
Jersey  City.  . 
Pittsburg  
Nashua  
Cincinnati.  .  . 

112X112 
45X100 
20X155 
38  X   94 
100X120 
100X200 

4 
5 
9 
6 

4 
8 

200 

74,000 
52,000 
212,500 
39,000 
61,500 
117,000 

82,500 
72,000 
196,000 
43,000 
63,600 
131,000 

10.3  more 
27  .  7  more 
6.  3  less 
9.3  more 
3.3  more 
10  .  7  more 
4  .  0  more 

Bid 
Est. 
Bid 
Bid 
Bid 
Bid 
Bid 

Bakery  .... 
Shop 

Cincinnati.  .  . 
Cincinnati 

60,000  s.f. 

300 

64,000 
16  000 

62,500 
19  100 

2  .  3  less 
16  2  more 

Bid 

Est 

Shop  .  .  . 

New  England 

65  800 

69  500 

Est 

Comparing  now  the  ultimate  cost  of  the  two  types.  For  con- 
venience, a  wooden  building  will  be  assumed  at  $100,000,  and  a 
concrete  building  10  per  cent,  more  or  $110,000,  and  the  con- 
tents in  each  case  will  be  assumed  of  equal  value  to  the  building. 
The  yearly  maintenance  cost  of  each  will  therefore  be  as  follows: 


150     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Wood  Reinforced  concrete 

Depreciation  at  1  1/2  per  cent $1,500  at  1/2  per  cent ...   $  500 

Insurance  on  bldg.  at  80  cents 800  at  20  cents 220 

Insurance  on  contents  at  $1.10 1,100  at  80  cents 880 

Interest  and  taxes  at  7  per  cent 7,000  7,700 

Oscillation,  vibration  at  1  per  cent. . .  .    1,000  


Total., .$11,400  $9,300 

The  reinforced  concrete  building  costing  $110,000  will  then 
have  a  maintenance  cost  of  $2100  per  year,  or  ^.1  per  cent,  less 
than  the  wooden  one  at  $100,000,  and  this  difference  of  $2100  at 
6  per  cent.,  is  interest  on  $35,000.  It  would,  therefore,  be  per- 
missible to  invest  an  additional  $35,000  on  a  concrete  building, 
to  make  the  two  types  of  equal  ultimate  cost.  A  concrete  build- 
ing costing  $145,000  or  45  per  cent,  more,  has  therefore  no  greater 
ultimate  cost  than  a  wooden  one  at  $100,000. 

In  comparing  the  cost  of  fireproofed  steel  construction  with 
reinforced  concrete,  complete  framing  and  exterior  curtain  walls 
being  considered  in  both  cases,  it  will  be  found  that  for  imposed 
floor  loads  of  150  Ib.  per  square  foot  or  more,  concrete  will  be 
cheaper  than  steel  by  5  to. 20  per  cent.,  depending  on  conditions. 
For  light  loads,  the  cost  of  the  two  types  will  be  nearly  equal, 
and  in  some  cases  with  very  light  load  and  long  spans,  steel 
framing  will  be  slightly  cheaper.  One-story  buildings  over 
large  areas  are  best  when  framed  in  steel. 

A  comparison  made  by  the  writer,  on  a  building  costing  'about 
$50,000,  for  total  floor  loads  of  200  Ib.  per  square  foot,  showed 
that  one  with  fireproofed  steel  framing  and  heavy  wooden  floor, 
cost  12  per  cent,  more  than  one  of  reinforced  concrete  with  grano- 
lithic floor  surface.  It  appears,  therefore,  that  factory  build- 
ings of  reinforced  concrete  have  the  lowest  cost  of  any  fire- 
proof construction  that  is  yet  available. 

The  following  table  gives  the  comparative  cost  of  a  variety 
of  buildings  of  different  kinds,  in  both  reinforced  concrete  and  in 
steel.  It  shows  that  the  former  type  is  cheaper  than  the  latter 
by  3  to  13  per  cent. 

From  comparative  estimates  made  by  the  writer  for  a  building 
of  500,000  cu.  ft.,  to  determine  the  comparative  cost  of  fire- 
proofed  steel  construction  and  wood  mill  framing,  it  appears 
that  one  with  complete  fireproofed  steel  frame,  side  curtain 
walls  and  wood  floors,  costs  30  per  cent,  more  than  wood  mill 
construction,  while  the  same  building  with  only  interior  fire- 


WOOD,  CONCRETE  AND  STEEL  BUILDINGS     151 


TABLE  XIII.— COMPARATIVE    COST  OF  BUILDINGS  IN   REINFORCED  CON- 
CRETE  AND  IN  STEEL* 


Kind 

Place 

Size 
ft. 

Sto- 
ries 

Load 
Ibs. 

Cost  of 
rein- 
forced 

Cost  of 
steel 

Re-con, 
more  or  less 
than  steel 

concrete 

Factory.  .  .. 

Des  Moines.  . 

66  X  132 

6 

200 

$60,650 

$69,750 

13%  less.... 

Est. 

Factory  .... 

Fairmount... 

50  X  100 

3 

200 

25,000 

28,000 

10.  7  less.... 

Bid 

Warehouse 

Brooklyn..  .  . 

140X190 

10 

200 

250,000 

280,000 

10.7  less.... 

Bid 

Office  

St.  Louis..  .  . 

86  X  120 

8 

70 

170,000 

184,000 

7.  6  less.... 

Bid 

Office  

Cincinnati.  .  . 

17 

70 

4.0  less.... 

Bid 

Mill  

Boston  

3 

278,200 

286,400 

2  .  8  less  

Bid 

Cambridge.  . 

60X320 

5 



90,000 

87,300 

3.3  more.  . 

Bid 

Store  

Indianapolis. 

71X120 

6 

125 

89,500 

96,000 

6.  8  less.... 

Bid 

Hospital.  .  . 

Indianapolis. 

6 

793,000 

823,000 

3.6  less.  ... 

Bid 

Hotel  

St.  Louis...  . 

120X140 

8 

70 

171,000 

184,000 

7.0  less.... 

Bid 

Hotel  

St.  Louis..  .  . 

11 

70 

290,000 

304,000 

4.6  less..  .  . 

Bid 

Factory.  .  .  . 

Ohio  

12 

200 

40,000 

less  than 

steel  

Bid 

Loft  

Springfield.  . 

105X283 

9 

150 

280,000 

320,000 

12.  5  less.... 

Bid 

proofed  steel  frame  and  solid  bearing  walls,  cost  19  per  cent, 
more  than  wood.  If  the  first  building  mentioned  above  had  a 
reinforced  concrete  floor,  its  cost  would  be  37  per  cent,  more 
than  wood  mill  construction,  while  the  corresponding  cost  of  the 
second  one  with  reinforced  concrete  floor  would  be  26  per  cent, 
more. 

1  J.  P.  H.  Perry,  in  Engineering  Magazine,  July,  1911. 


CHAPTER  XII 

-f* 

FOUNDATIONS 

Permanent  buildings  should  have  substantial  foundations, 
for  on  them  depends  the  stability  of  the  whole  erection.  Under 
this  heading  is  considered,  the  sub-strata  or  soil  on  which  the 
building  stands  as  well  as  the  footing  courses  or  masonry  below 
ground  level.  Foundations  for  factory  buildings  are  usually  not 
difficult,  for  a  site  will  have  been  selected  with  due  regard  for 
economy  in  this  direction,  so  the  subject  will  be  discussed  only 
briefly.  Any  effort  at  exhaustive  treatment  would  in  itself,  fill 
a  whole  volume.  Foundations  must  be  provided  not  only  for  the 
buildings,  but  also  for  machinery,  yard  cranes,  water  towers 
and  other  works  about  the  plant,  and  enough  foresight  must  be 
used  to  provide  space  or  openings  through  the  walls  for  power 
tunnels  or  for  lines  of  pipe,  sewers,  service  mains  or  conduits. 

Loads. — The  loads  which  the  foundations  must  sustain 
can  be  computed  approximately  from  preliminary  building 
plans,  and  from  the  weight  of  machinery  and  appliances  as  re- 
ported by  their  makers.  Floor  loads  will  have  been  established, 
and  these,  together  with  their  dead  weight,  will  be  transmitted 
through  the  framing  to  the  ground.  From  the  known  weight 
of  masonry  and  other  building  materials  and  the  approximate 
rules  for  weight  of  framing  as  given  in  previous  chapters,  the 
total  weight  on  the  soil  can  be  determined.  Impact  from 
cranes  and  machinery,  to  the  extent  of  50  to  100  per  cent,  of  the 
live  load,  must  in  some  cases  be  added,  and  sometimes  the  over- 
turning effect  of  wind  on  the  leaward  side. 

Bearing  Power  of  Soils. — The  best  method  of  determining  the 
safe  bearing  power  of  soils,  is  by  loading  small  known  areas  and 
observing  the  settlement.  In  many  cases  this  may  not  be  neces- 
sary, as  an  experienced  builder  can  decide  the  matter  by  inspec- 
tion or  by  very  simple  examination.  But  when  there  is  any 
doubt,  tests  or  borings  should  be  made.  So  many  buildings 
have  been  permanently  injured  by  uneven  settlement,  that  it  is 
folly  to  assume  risks  in  this  direction  when  the  condition  of  the 

152 


FOUNDATIONS  153 

ground  can  easily  be  found  at  slight  expense.  When  soundings 
are  desirable,  they  should  be  made  under  the  site  of  the  proposed 
building  and  not  simply  near  it.  The  best  method  of  discover- 
ing soil  conditions  is  by  digging  test  pits,  though  a  quicker  way 
is  with  a  large  wood  auger  fastened  to  a  rod  or  pipe.  The  test 
pit  gives  the  greatest  opportunity  for  examining  the  strata. 

For  the  purpose  of  taking  soundings,  sections  of  pipe  about 
1J  inches  diameter,  can  be  driven  into  the  ground  with  the 
assistance  of  a  water  jet  when  necessary,  the  driving  being  done 
with  a  wooden  mallet.  The  upper  end  of  the  pipe  should  be 
protected  by  a  cap,  and  new  sections  of  pipe  may  be  spliced  as 
needed. 

The  safe  bearing  value  of  different  kinds  of  soil,  as  used  by  the 
United  States  government  engineers,  is  as  follows: 

TABLE  XIV 

Rock 200  tons  per  square  foot 

Gravel,  cemented 8  to  10  tons  per  square  foot 

Sand,  compact  and  clean . .  4  to    6  tons  per  square  foot 

Sand,  ordinary 2  to    4  tons  per  square  foot 

Dry  stiff  clay 4  to    6  tons  per  square  foot 

Moderately  dry  clay 2  to    4  tons  per  square  foot 

Dry  earth 1  to    2  tons  per  square  foot 

Quicksand  and  wet  soil ....  1/2  to    1  ton  per  square  foot 

The  bearing  power  of  soils  may  sometimes  be  increased  by  drain- 
ing, or  compressing  the  earth,  or  a  firmer  strata  may  be  found 
at  greater  depth.  In  other  cases  piles  may  be  driven. 

Area  on  the  Soil. — From  the  nature  of  the  ground  as  revealed 
by  soundings  or  test  pits,  a  safe  bearing  load  per  square  foot  can 
be  determined,  and  from  the  weight  of  the  building  as  found  by 
computation,  the  area  of  base  can  be  proportioned.  Founda- 
tion loads  are  rarely  assumed  greater  than  1  to  2  tons  per  square 
foot. 

In  proportioning  the  foundation  area  to  the  load  upon  it,  an 
effort  need  not  be  made  to  eliminate  all  settlement,  but  rather 
to  so  plan  the  building  that  whatever  settlement  does  take  place, 
will  be  uniform.  With  this  in  mind  it  will  be  seen  that  it  is  often 
as  great  an  injury  to  make  some  parts  too  large  as  it  would  be  to 
make  them  small,  for  they  would  then  not  settle  at  the 
same  rate.  Rock  foundation  is  satisfactory  when  it  underlies 
the  whole  building,  though  cranes  and  machinery  may  run  easier 
when  founded  on  earth  or  timber.  Rock  under  some  parts  and 


154     ENGINEERING  OF  SHOPS  AND  FACTORIES 

earth  under  other  parts,  is  not  desirable,  for  the  first  is  unyield- 
ing while  earth  will  compress,  to  some  extent.  Therefore,  in 
passing  from  rock  to  earth,  the  footing  courses  should  be  spread 
out  over  the  softer  material  so  the  pressure  per  square  foot  on 
the  soil  adjoining  the  rock  will  be  less  than  it  is  further  away. 
Sloping  rock  must  be  dressed  off  into  horizontal  steps.  Loam  is 
seldom  reliable,  and  sand,  gravel  anct  hard  pan  are  the  best,  for 
they  are  firm  and  can  easily  be  drained.  Trenches  through 
earth  and  clay  should  have  layers  of  sand  and  gravel  rammed  in 
solid  to  fill  the  whole  width  of  trench  from  side  to  side.  Soft 
strata  overlaid  with  a  layer  of  hard  material,  6  to  8  ft.  thick,  is 
usually  safe. 

The  footings  must  be  far  enough  under  ground  to  be  below 
the  reach  of  frost,  and  should  go  down  to  the  original  bed  below 
any  recent  filling. 

The  cost  of  excavation  without  shoring  will  be  about  as  follows : 

General  excavation  in  soft  material,  costs  25  to  50  cents  per  cubic  yard. 
Trench  excavation  in  soft  material,  costs  50  to  100  cents  per  cubic  yard. 
Trench  excavation  in  rock  material,  costs  $1.00  to  $2 . 00  per  cubic  yard. 

Foundation  Walls. — Brick  should  be  clean  and  wet  before 
laying,  and  basement  walls  should  receive  two  coats  of  tar  on 
the  exterior  before  filling  earth  in  behind  them.  Continuous 
walls  are  frequently  the  best,  especially  when  columns  are 
fairly  close  together,  but  separate  piers  are  cheaper  when  they 
are  far  apart. 

Piers. — Interior  columns  may  be  arranged  to  deliver  their 
loads  (1)  on  a  solid  slab  of  concrete  covering  the  whole  shop 
basement,  (2)  on  separate  concrete  bases  extending  over  to  the 
adjoining  wall  columns,  or  (3)  on  independent  interior  piers. 
The  first  of  these  methods  was  used  in  1886  in  a  New  England 
mill  50  by  80  ft.  in  plan,  a  solid  mass  of  concrete  3  ft.  thick  being 
placed  under  the  whole  building,  but  a  more  modern  and  im- 
proved method  is  shown  in  Fig.  80. 

Individual  piers  should  have  several  offset  footing  courses 
(Fig.  81)  rather  than  building  them  as  truncated  concrete  cones 
(Fig.  82) ,  for  in  the  first  method  the  forms  are  more  easily  made. 
The  projecting  courses  should  be  small  enough  so  they  will  not 
crack,  and  successive  layers  should  generally  spread  out  at  an 
angle  not  exceeding  30  degrees  with  the  vertical.  Spread  con- 
crete footings  can  also  be  made  in  octagonal  form  with  plain  or 
roughened  reinforcing  bars  in  four  directions.  Bars  may  gener- 


FOUNDATIONS 


155 


ally  be  ^  to  J  in.  diameter,  and  3  to  12  in.  apart.  Other 
bases  may  be  made  with  beams  or  track  rails  in  two  directions, 
embedded  in  concrete,  or  timber  foundations  can  be  used  in 
places  where  they  will  be  always  wet  or  always  dry.  When 


SecHon      C-D. 


H- 

Col.3. 


Plan. 

-•H<- --id'o-'- i....>j<.... 

Col.  4.       4"Goncrete  Fl.Slab          Col. 5. 


JJIiii  I  ^T- » J  JjjIiL  fy*^11- ... ..  Jj 


Section       A~B. 

FIG.  80. — Foundation  slab  for  a  building  over  quicksand. 

stone  is  used  in  piers,  it  must  lie  flat  on  its  natural  bed,  but  on 
account  of  their  better  bond,  hard  bricks  or  concrete  are  prefer- 
able. Piers  should  be  large  enough  so  the  pressure  on  them 
will  not  exceed  250  Ib.  per  square  inch  on  stone,  or  150  to  200 


156     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Ib.  on  brick,  and  they  should  be  capped  with  a  block  of  cut  stone, 
fine  moulded  concrete,  or  cast  iron.  The  thickness  of  masonry 
caps  should  not  be  less  than  one-fifth  of  their  longest  side. 

Notwithstanding  general  rules,  each  case  must  have  separate 
thought  and  study,  for  it  may  need  some  special  treatment. 

Piles. — Bearing  piles  may  be  either  of  wood  or  concrete,  and 
sheet  piles  of  wood  or  steel. 

The  top  of  wooden  piles  should  always  be  under  water  to 
prevent  decay,  because  timber  rots  when  alternately  wet  and 
dry.  They  should  generally  be  driven  until  the  penetration 
under  the  last  blow  of  a  2000-lb.  hammer  does  not  exceed  1  in., 
though  this  is  not  an  absolute  rule,  for  in  certain  places  as  along 
the  river  at  Buffalo,  ground  is  so  soft  as  to  shake  for  100  ft.  in 
every  direction  when  the  hammer  falls. 


FIG.  81.  FIG.  82. 

Saunder's  rule  for  the  safe  load  on  piles  is, 

i  *    i     A   '  3#  w 

Safe  load,  in  pounds,  =-^-  -~- 

while  another  and  more  recent  formula  is, 

,  ,   .      ,   .  2WH 

Safe  load,  in  pounds,  =  <^rr 

In  both  of  the  above,  W  is  the  weight  of  hammer  in  pounds 

H  is  the  fall  of  the  hammer  in  feet,  and 
S    is    the    penetration    in    inches    under 

the  last  blow. 

Piles  depending  on  friction  will  generally  safely  support  10  to 
15  tons  each,  though  never  more  than  25  tons.  They  should 
have  an  iron  ring  fitted  over  their  head  when  there  is  a  tendency 
to  split,  and  they  may  also  have  pointed  cast-iron  shoes  when 
necessary,  though  this  adds  to  the  expense  and  is  often  no 
better  than  pointing  the  pile  itself.  They  can  be  driven  2£ 
to  3  ft.  apart,  and  when  sawed  off  level,  they  should  be  capped 
with  timber  grillage  or  a  solid  slab  of  concrete  2  to  3  ft.  thick 
extending  down  over  the  pile  heads.  Wooden  piles  usually 
cost  25  to  35  cents  per  lineal  foot  in  place. 


FOUNDATIONS 


157 


Concrete  piles,  because  of  their  greater  permanence,  are  com- 
ing into  favor  more  than  wood.  They  are  made  in  several  ways, 
each  of  which  is  patented.  The  average  cost  of  concrete  piles 
in  place  is  $1  to  $1.25  per  lineal  foot. 

Sheet  piling  (Fig.  83)  is  plank 
connected  with  tongue  and 
groove,  or  splines,  and  it  can 
best  be  driven  by  light  and  rapid 
blows,  for  the  wood  is  then  less 
likely  to  split.  Coffer  dams  con- 
sist of  two  rows  of  sheet  piling  3 
to  5  ft.  apart,  filled  in  between 
with  clay  puddle.  To  prevent 
overturning,  the  width  between 
the  inner  and  outer  row  of  sheet- 
ing must  be  proportioned  to  the 
depth  of  water  in  which  it 
stands. 

Engine  Foundations. — Light 
machinery  even  when  founded 
on  masonry,  will  run  smoother 
when  bolstered  up  on  timber. 

Masonry  foundations  should  be  laid  in  cement  mortar.  Those 
under  steam  hammers  must  have  some  spring  and  in  this  case 
solid  timber  is  preferable  to  masonry,  though  a  cushion  of 
asphalt  will  assist  in  destroying  vibration.  The  anvil  founda- 


FIG.  83. — Detail  of  sheet-piling. 


FIG.  84. 


tion  directly  under  the  hammer  should  be  separate  and  discon- 
nected from  that  which  supports  the  bearings  at  either  side, 
so  the  impact  from  the  blows  will  be  transmitted  directly  to  the 
earth,  without  jarring  the  other  bases. 


CHAPTER  XIII 
GROUND  FLOORS1 

Factory  floors  may  be  divided  into  £wo  general  classes,  ground 
floors,  and  upper  floors,  and  in  each  case  a  distinction  must  be 
made  between  the  structural  parts,  and  the  wearing  surface  or 
finish.  The  various  kinds  of  floors  will  first  be  'described  in 
order,  after  which  will  be  given  the  types  which  are  best  suited 
for  different  shops  and  industries,  the  choice  depending  in  each 
case  upon  the  character  of  work  done,  and  the  size  and  weight 
of  products  and  machinery.  Wood,  asphalt,  clay,  brick,  con- 
crete, and  metal,  are  all  suitable  in  their  places,  and  they  will  be 
described  in  detail  in  later  pages.  In  some  buildings  such  as  forge 
shops,  a  dirt  or  cinder  floor  is  the  best,  while  only  a  hard  and 
dustless  surface  is  suitable  in  rooms  where  fine  instruments  are 
made. 

Ground  floors  should  be  built  like  good  street  pavements, 
being  extra  solid  for  heavy  work  and  loads,  and  less  permanent 
for  lighter  service.  The  common  forms  are:  (1)  earth,  (2)  wood 
block,  (3)  plank  floors,  (4)  tar-concrete  and  wood,  (5)  cement- 
concrete  and  granolithic,  (6)  asphalt,  and  (7)  brick. 

Shop  floors  should  generally  have  a  slight  grade,  preferably 
in  the  direction  of  the  greatest  travel,  not  only  to  facilitate 
drainage,  but  also  to  make  easier  the  starting  and  movement  of 
loaded  trucks  and  cars.  Where  water  is  freely  used,  as  in  car 
sheds  and  round  houses,  good  drainage  is  imperative,  for  the 
best  work  cannot  be  done  when  men  are  standing  in  water  with 
their  feet  wet.  In  the  construction  of  steel  frame  buildings,  the 
contract  for  which  is  frequently  placed  with  a  structural  steel 
company  in  a  distant  city,  the  ground  floor  can  usually  be  more 
cheaply  made  by  a  builder  who  is  familiar  with  local  conditions 
and  the  source  of  supplies. 

Earth  Floors. — These  are  perhaps  the  simplest  kind  of  shop 
floors.  There  should  first  be  laid  a  bed  of  sand,  over  which  cin- 
ders are  spread,  and  this  should  be  well  compressed  and  flooded 
with  a  hose  every  day  for  two  or  three  weeks,  being  rolled  each 
time  after  wetting.  Instead  of  cinders,  a  mixture  composed  of 

1  H.  G.  Tyrrell,  in  Engineering  Magazine,  July-August,  1912. 

158 


GROUND  FLOORS  159 

one  part  of  clay  with  three  of  gravel  may  be  used,  spread  8  to 
12  in.  deep  and  rammed,  the  clay  acting  as  a  cement  or  binder 
for  the  gravel.  In  any  case,  the  floor  must  have  a  top  layer  of 
fine  cinders  or  sand  to  prevent  mud  from  forming  on  the 
surface. 

Wood  Block  Floors. — Wood  blocks  make  an  excellent  shop 
floor — one  that  is  easy  to  walk  upon,  with  little  or  no  liability  to 
slipping.  When  not  subject  to  moisture  or  water  soaking,  the 
blocks  can  be  used  in  their  natural  condition,  and  they  must 
then  be  laid' with  1/4-in.  open  joints  for  expansion,  the  joints 
being  filled  in  with  sand.  When  exposed  to  weather,  the  blocks 
should  be  creosoted  and  the  joints  filled  with  sand  and  pitch  or 
cement  grout.  The  flour  should  then  endure  for  ten  to  twenty 
years. 

A  good  specification  for  a  wood  block  floor  is  to  first  spread 
and  thoroughly  compact  a  layer  of  gravel  or  cinders  12  in.  deep 
over  which  is  laid  4  in.  of  concrete.  One  or  two  inches  of  sand 
is  then  spread  and  rolled,  and  on  this  are  placed  the  wood  blocks. 
A  modification  of  this  floor  was  used  in  a  large  shop,  330  ft.  wide 
and  776  ft.  long,  for  the  American  Bridge  Company  at  Ambridge, 
Pa.  The  slag  base  was  first  spread  and  rolled,  and  on  this  was 
placed  a  6-in.  layer  of  tarred  gravel  covered  with  1  in.  of  tarred 
sand.  On  this  were  set  the  maple  and  beech  paving  blocks,  which 
were  4  by  4  in.,  8  in.  long,  the  grain  of  the  wood  being  vertical. 

Instead  of  the  concrete  base  above  described,  a  2-in.  layer 
of  sand  is  sometimes  spread  over  the  bottom  course  of  gravel  or 
cinders,  and  2-in.  plank  laid  thereon,  as  a  base  for  the  wood 
blocks.  This  latter  method  has  the  disadvantage  that  the  plank 
distributes  vibrations,  and  as  the  plank  decays,  a  larger  area 
must  be  removed  for  renewing  or- replacing  it.  This  type  of 
floor,  with  oak  blocks  5  in.  high  and  6  to  12  in.  long,  was  used  in 
the  car  shops  for  the  Illinois  Central  Railway  Company  at  Chicago. 
The  base  of  2  by  12  in.  hemlock  planks  was  laid  on  sleepers 
embedded  in  sand. 

Wood  blocks  may  be  used  also  for  upper  floors  by  placing  un- 
der them  two  layers  of  paper  laid  in  pitch,  and  joining  the  blocks 
with  paving  pitch  and  sand.  This  floor  is  suitable  also  in 
foundries  excepting  within  a  few  feet  of  the  ovens. 

Plank  Floors. — Wood  floors  are  the  most  comfortable  to  walk 
and  work  upon,  and  are  usually  the  best  excepting  in  places 
where  they  would  be  destroyed  by  chemicals,  moisture  or  heat. 


160     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  comfort  of  employees  in  working  on  wood  floors  is  impor- 
tant and  worth  considering,  for  men  can  do  their  best  work  only 
when  contented  and  comfortable.  The  preference  of  workmen 
in  this  respect  is  shown  by  the  replies  received  from  forty  dif- 
ferent factories,  from  twenty-six  of  which  a  decided  choice  was 
expressed  for  wood  over  any  other  kind  of  wearing  surface. 
Pine  flooring  is  perhaps  the  best  when  the  life  has  not  all  been 
tapped  out  of  the  tree  before  sawing  it  into  boards.  Flooring 
boards  for  upper  surface  should  not  exceed  3  to  4  in.  in  width,  and 
they  should  have  hollow  backs  and  be  laid  in  the*:  direction  of 
the  greatest  travel.  Seven-eighth-inch  flooring  is  quite  as  good 
as  one  and  one-eighth,  for  when  the  thinner  boards  are  worn 
away  enough  for  renewal,  it  would  also  be  time  to  replace  the 
thicker  one.  Maple  wearing  surface  in  short  lengths  is  satis- 
factory, for  it  can  be  easily  repaired.  Two  layers  of  tar  paper 
should  be  placed  between  the  upper  and  lower  courses.  The 
lower  course  should  preferably  span  two  bays  or  panels  for  the 
sake  of  greater  strength  or  stiffness.  Planks  3  in.  thick  or 
more  should  have  splines  rather  than  tongue  and  groove,  though 
when  floors  are  used  for  trucking,  the  upper  boards  should  have 
square  edges,  as  grooved  edges  break  under  heavy  loads  and 
wheels.  Blind  or  edge  nailing  interferes  with  repairs  and  is, 
therefore,  not  desirable.  Four-inch  planks  should  have  7-in. 
steel  spikes,  one  keg  of  100  Ib.  being  enough  to  lay  1200  sq.  ft. 
of  floor. 

All  wood  floors  have  the  disadvantage  that  water  used  in 
cleaning  them  will  soak  into  the  cracks  -and  cause  the  boards 
to  expand  and  form  ridges.  It  is  important,  therefore,  to 
devise  methods  for  preserving  them,  one  good  process  being 
that  of  creosoting.  In  this  process,  the  wood  is  first  dried  and 
the  creosote  oil  is  then  forced  into  it  under  a  pressure  of  150  Ib. 
per  square  inch.  Unseasoned  timber  must  remain  unpainted, 
for  paint  on  such  material  is  worse  than  none  at  all.  After  two 
or  three  years,  when  the  wood  is  dry,  it  should  receive  three  coats 
of  oil  paint.  The  timber  must  also  be  well  ventilated  to  pre- 
vent destruction  from  dry  rot. 

A  very  cheap  and  temporary  floor  ismade  by  placing  3-in.  plank 
on  half-round  timbers,  3  ft.  apart,  embedded  in  6  to  8  in.  of  cin- 
ders, the  wood  being  coated  on  the  under  side  with  lime.  Its 
cost  is  very  low,  being  only  50  cents  per  square  yard.  A  floor 
similar  to  this  with  2-in.  plank  on  chestnut  slabs,  embedded  in 


GROUND  FLOORS  161 

gravel  over  made  ground,  decayed  within  a  year,  and,  there- 
after, about  half  of  it  was  replaced  annually.  In  the  immediate 
vicinity  was  another  floor  with  2-in.  plank  on  3  by  12-in.  joists, 
supported  on  12  by  12-in.  sills  and  masonry  piers,  which  required 
no  renewal  for  twelve  years.  A  floor  similar  to  those  described 
above,  with  sills  embedded  in  sand  instead  of  cinders,  was  used 
twenty-five  years  ago  in  a  shop  for  William  Sellers  and  Company, 
of  Philadelphia,  an  effort  being  made  to  preserve  the  plank  by 
placing  under  it  a  layer  of  resin  I  in.  thick. 

Three  other  temporary  wooden  floors  may  be  mentioned;  the 
first  has  |-in.  flooring  over  2-in.  plank  with  sleepers  embedded 
in  gravel;  the  second  has  4-in.  plank  on  sills  laid  in  broken  stone; 
and  the  third,  3-in.  plank  on  4  by  6-in.  sills,  4  ft.  apart,  embedded 
in  about  6  in.  of  cinders.  These  have  the  advantage  of  low  cost, 
the  last  costing  not  over  10  to  12  cents  per  square  foot,  with 
lumber  at  $30  per  thousand,  board  measure.  If  a  concrete  base 
is  used  instead  of  cinders,  the  cost  would  be  25  to  30  cents  per 
square  foot. 

A  floor  heavy  enough  to  carry  ordinary  machinery  anywhere 
without  special  foundations  is  made  by  first  laying  and  ramming 
an  8-in.  concrete  base,  after  which  6  by  6-in.  timbers  are  placed 
3  to  4  ft.  apart,  and  the  space  between  them  filled  with  concrete, 
after  which  a  3  in.  floor  was  laid.  A  still  heavier  floor  of  the  same 
kind  with  a  solid  layer  of  concrete,  2  ft.  thick,  covered  with  plank 
on  sleepers,  will  permit  heavy  machines  to  be  set  anywhere  with- 
out special  foundations.  Such  a  floor  was  used  in  the  erecting 
shop  of  the  Allis-Chalmers  plant,  at  Milwaukee,  Wis. 

A  similar  but  lighter  floor  with  2-in.  maple  wearing  surface 
and  1  by  |-in.  splines,  was  used  in  the  Santa  F6  Railway 
shops,  the  maple  flooring  being  spiked  to  3  by  4-in.  yellow  pine 
sleepers  18  in.  apart,  embedded  in  6  in.  of  concrete.  In  this 
case  the  concrete  and  sleepers  without  the  flooring  cost  8  to  9 
cents  per  square  foot.  In  the  McKees  Rocks  railroad  shops, 
wire  conduits  were  placed  below  the  floor  at  intervals  of  5J 
ft.,  for  receiving  the  light  and  power  wires  for  the  machines.  A 
layer  of  concrete  4  in.  thick  was  first  spread  and  covered  with 
five  sheets  of  tarred  felt  in  hot  tar;  over  which  was  spread  an 
inch  of  sand.  On  this  layer  of  sand,  4  by  4-in.  sleepers  were  laid 
and  filled  between  with  more  sand,  over  which  was  spiked  a 
course  of  2f-in.  pine  plank,  and  a  wearing  surface  of  IJ-in. 
tongue  and  groove  maple.  The  railway  shops  at  Parsons,  Kan., 
11 


162     ENGINEERING  OF  SHOPS  AND  FACTORIES 

have  a  somewhat  similar  floor  excepting  that  the  wearing  sur- 
face is  4  by  l|-in.  white  oak  with  a  layer  of  roofing  felt  be- 
tween the  upper  and  lower  courses.  The  3  by  4-in.  yellow  pine 
sleepers  were  treated  by  the  zinc  process  to  preserve  them,  and 
the  space  between  them  filled  with  dry  sand.  They  were  laid 
on  an  inch  of  sand  and  tar  over  a;  6-in.  bed  of  broken  stone. 
Floors  of  this  general  type  with  slight  modifications  are  numerous, 
showing  the  favor  with  which  they  are  received. 

One  man  will  lay  2^  squares  (250  sq.  ft.)  per  day  of  eight 
hours  on  upper  floors  including  the  hoisting,  and  three  squares 
per  day  at  street  level.  Laying  sleepers  costs  $4  to  $4.50  per 
thousand  feet,  board  measure,  and  3-in.  flooring  about  $3  per 
thousand. 

No.  1,  Y.P.  2  X 6-in.  tongue  and  groove,  costs  $8  to  $10  per  square  laid. 
No.  1,  Y.P.  3X6-in.,  tongue  and  groove,  costs  $13  per  square  laid. 
4X|-in.  Y.P.  tongue  and  groove,  costs  $7  to  $8  per  square  laid. 
6X|-in.  Y.P.,  tongue  and  groove,  costs  $5  to  $6  per  square  laid. 
4Xl-in.  W.P.,  tongue  and  groove,  costs  $8.50  to  $10  per  square  laid. 
2£   x  If-in-  clear  maple,  tongue  and  groove,  costs  $11  to  $13  per  square 
laid. 

Floors  of  Tar-concrete  and  Wood. — An  excellent  shop  floor 
consists  of  a  base  of  concrete  and  tar  or  asphalt,  with  a  wood 
wearing  surface.  Over  a  mixture  of  tar,  the  wood  is  preserved, 
while  over  cement  concrete  it  decays  quickly,  and  over  dead 
air  space,  it  succumbs  to  dry  rot.  A  floor  of  concrete  and  tar 
with  wood  top  is  solid,  without  vibrations,  tools  do  not  break 
when  they  fall,  and  machines  may  be  screwed  to  the  floor  any- 
where. It  is  nearly  fireproof  because  there  are  no  sleepers  and 
no  air  space  beneath  the  wood.  It  is  not  expensive,  and  will 
last  from  twenty  to  twenty-five  years,  while  the  wood  top  makes 
it  comfortable  to  walk  upon.  It  is  laid  by  first  spreading  a 
4-in.  layer  of  screened  gravel  or  stone  not  larger  than  2£  in., 
mixed  with  tar.  The  tar  should  be  heated  to  200°  F.,  and  enough 
added  so  the  mixture  will  be  compact  when  rolled,  the  amount 
of  tar  required  for  different  kinds  of  aggregate  being  as  follows : 

Stone  2^  in.  to  1  in.  diam.  use 6  gallons  of  tar  per  cubic  yard 

Stone  2|  in.  to  £  in.  diam.  use 9  gallons  of  tar  per  cubic  yard 

Coarse  gravel 7  gallons  of  tar  per  cubic  yard 

Fine  gravel 10  gallons  of  tar  per  cubic  yard 

The  sand  and  gravel  should  be  well  heated  before  the  tar  is 
added.     Over  hard  ground,  2  or  3  in.  of  tarred  stone  may  be 


GROUND  FLOORS  163 

enough.  No  economy  results  from  using  cinders  or  sand  in  pre- 
ference to  stone  for  the  bottom  covering,  for  cinders  require  15  gal- 
lons of  tar  per  cubic  yard,  and  sand,  20  gallons.  Stone  at  $1 .25  per 
cubic  yard  has,  therefore,  no  greater  ultimate  cost  than  cinders 
at  50  cents  per  yard.  In  some  cases,  4  to  6  in.  of  cement  con- 
crete is  used  for  a  base  course,  instead  of  the  tar-concrete  above 
specified,  but  when  this  is  done,  it  should  receive  a  coat  of  tar 
before  laying  the  sand.  Over  this  base  of  concrete  is  spread 
a  1-in.  layer  of  sand  and  tar,  mixed  in  the  proportion  of  50  to  60 
gallons  of  tar  to  each  yard  of  sand.  This  mixture  should  be 
heated  to  225°  F.,  spread  1^  in.  thick  and  rolled  down  to  1  in. 
While  it  is  yet  warm  and  soft,  a  layer  of  3-in.  plank  is  embedded 
therein,  over  which  is  laid  a  top  wearing  surface  of  maple. 
The  cost  of  a  floor  made  of  cinders  and  tar  6-in.  deep,  overlaid 
with  3-in.  plank  on  3  by  4-in.  sleepers,  16  in.  on  centers,  embedded 
on  the  cinders,  is  as  follows : 

Cinders  and  tar 8  cents  per  square  foot 

Wood 16  cents  per  square  foot 

In  the  above,  one  barrel  of  tar  was  used  with  eight  barrels  of 
cinders.  With  tar  at  $2  to  $5  per  barrel,  the  cost  of  these  floors 
should  not  exceed  24  to  30  cents  per  square  foot.  A  floor  of 
this  kind  in  a  shop  for  the  Boston  and  Albany  Railroad  Com- 
pany, with  a  4-in.  layer  of  coal-tar-concrete,  overlaid  with  one 
inch  sand  and  ^-in.  roofing  pitch,  with  two  layers  of  spruce 
plank,  2J  and  1J  in.  thick,  cost  in  1898  only  18  cents  per 
square  foot.  Without  the  wood  work,  the  cost  of  base  with 
stone,  sand  and  tar  should  not  exceed  10  to  13  cents  per  square 
foot. 

This  type  of  floor  has  been  used  with  many  modifications. 
In  one  shop  cement  concrete  was  laid  6  to  12  in.  thick,  with 
4  by  4-in.  wood  strips  embedded  therein  2  ft.  apart.  Over  the 
strips  and  concrete,  was  spread  a  layer  of  fine  sand  and  coal  tar, 
in  which  the  lower  plank  course  of  2-in.  tongue  and  groove 
yellow  pine  was  laid  and  nailed.  The  wearing  surface  in  this 
case  was  4  by  IJ-in.  maple  with  square  edge.  Owing  to  the 
splitting  of  matched  flooring  under  trucks,  and  the  difficulty 
of  repairing  it,  square  edge  boards  are  frequently  preferred  for 
the  upper  course. 

Cement -concrete  Floors. — Floors  of  cement-concrete  should 
be  laid  similar  to  a  good  sidewalk  pavement,  with  cement  and 


164     ENGINEERING  OF  SHOPS  AND  FACTORIES 

aggregate  mixed  in  about  the  same  proportion.  In  determining 
the  proportion  of  materials  for  the  aggregate,  a  barrel  should  be 
filled  with  broken  stone,  or  the  largest  material,  and  the  amount 
of  water  that  can  be  added  to  the  barrel  thus  filled,  represents 
the  amount  of  gravel  or  fine-crushed  stone  that  it  will  hold. 
This  amount  of  gravel  and  .crushed  stone  should  then  be  placed 
in  another  barrel,  and  the  amount  of  water  that  can  be  added 
without  increasing  its  bulk  represents  the  amount  of  sand  needed. 
In  the  same  way,  the  required  amount  of  sand  should  be  placed 
in  another  vessel,  and  the  amount  of  water  that  it ' 'can  be  made 
to  hold  will  represent  the  required  amount  of  cement.  In  order 
to  have  all  voids  in  the  larger  material  well  filled  by  the  finer 
ones,  it  is  well  in  each  case  to  increase  the  amount  of  finer 
material  by  about  25  per  cent,  over  the  theoretical  amounts 
found  by  the  above  tests. 

For  making  these  experiments,  it  may  be  more  convenient  to  use 
a  box  of  exactly  one  or  two  cubic  feet  capacity,  and  the  proportion 
by  weight  may  be  determined  by  weighing  the  ingredients  as  found 
from  the  above  experiments.  To  obtain  the  proper  density  for  a 
water  tight  floor,  the  proportion  of  cement  should  generally  be  not 
less  than  1  part  of  cement  with  2J  of  sand  and  4J  of  larger  aggre- 
gate, though  in  some  cases  a  tight  floor  has  been  made  with  a  leaner 
mixture  at  a  proportionately  less  cost.  Unscreened  material  from 
a  sand  and  gravel  bed  are  sometimes  used,  but  as  their  relative 
amounts  are  uncertain,  it  is  usually  better  to  mix  them  in  definite 
known  proportions. 

One  barrel  of  cement  contains  3.8  cu.  ft.,  and  when  mixed  as 
directed  above,  the  concrete  will  cover  an  area  of  100sq..ft., 
2^  in.  deep. 

The  depth  of  excavation  and  filling  under  the  concrete  wilt 
depend  on  the  nature  of  the  subsoil  and  local  condition,  as  well 
as  on  the  carrying  capacity  of  the  floor,  a  wet  soil  requiring  a 
greater  depth  of  broken  stone  for  drainage.  A  heavy  floor  may 
be  strong  enough  to  support  large  machines  placed  anywhere, 
while  a  lighter  one  may  require  special  machine  foundations.  As  a 
general  guide  for  laying  concrete  floors,  the  following  directions 
are  given.  First,  excavate  the  soil  to  a  depth  of  15  to  22  in. 
below  the  finished  grade  level.  Then  spread  a  layer  of  broken 
stone  8  to  12  in  deep,  over  which  lay  4  to  6  in.  of  gravel  or  crushed 
stone,  thoroughly  tamped  and  rolled.  Then  spread  a  layer  of 
concrete  2  to  4  in.  thick  which  must  be  covered  while  it  is  still 


GROUND  FLOORS  165 

green  with  a  wearing  surface  J  to  2  in.  thick  (1  in.  being  the 
usual)  composed  of  cement  and  sand  in  the  proportion  of  1  to  1, 
or  1  to  2.  It  may  be  colored  if  desired,  and  should  be  leveled 
off  with  a  straight  edge  and  marked  into  squares  or  rectangles. 
Shrinkage  cracks  will  then  follow  regular  lines  instead  of  making 
irregular  breaks  through  the  pavement.  The  mixture  for  the 
wearing  surface,  should  be  thin  enough  so  that,  when  laid  and 
troweled  off,  the  cement  will  come  to  the  top  and  form  a  hard 
smooth  surface  when  dry.  It  is  important  that  the  lower  course 
be  green  or  mcist  when  the  wealing  surface  is  applied,  for  if 
dry,  the  upper  course  will  soon  crack  and  disintegrate.  The 
floor  should  be  protected  for  about  thirty-six  hours,  after  which 
it  is  ready  for  use. 

Instead  of  using  12  to  18  in.  of  broken  stone  and  gravel  as 
specified  above,  a  depth  of  5  to  6  in.  may  be  enough  in  some 
cases  for  light  floors  and  well  drained  subsoil,  the  cost  of  this 
lighter  construction  being  12  to  20  cents  per  square  foot.  A 
concrete  slab  6  in.  thick  with  J-in.  &urface  finish,  supported 
on  a  well-drained  base  of  gravel  or  broken  stone,  has  been  found 
satisfactory  for  round  houses,  though  somewhat  difficult  to 
repair. 

The  cost  of  a  floor  with  J-in.  surface  over  a  2-in.  concrete 
base,  is  as  follows: 

Cement 30  cents  per  square  yard 

Stone  and  sand 10  cents  per  square  yard 

Labor 26  cents  per  square  yard 


Total 66  cents  per  square  yard 

In  the  above,  the  labor  cost  of  surface  finish  is  14  to  15  cents  per 
square  yard,  and  for  a  greater  thickness  of  concrete  base,  the 
cost  would  be  increased  18  cents  per  square  yard  for  each  addi- 
tional inch  of  thickness.  A  light  floor  with  1-in.  wearing  surface 
and  concrete  only  4  in.  thick,  can  be  laid  at  the  rate  of  100  sq.  ft. 
per  day  of  eight  hours  for  each  man  employed,  the  cost  per 
square  foot  being 

Materials 9  cents  per  square  foot 

Labor 2  cents  per  square  foot. 


Total 11  cents  per  square  foot 

Assuming  sand  and  gravel  to  cost  $1  to  $1.25  per  cubic  yard, 
and  crushed  limestone,  $1.50  to  $1.75  per  cubic  yard,  the  cost 


166     ENGINEERING  OF  SHOPS  AND  FACTORIES 

of  concrete  may  be  taken  at  20  to  25  cents  per  cubic  foot,  and  a 
1-in.  surface  finish  at  5  to  6  cents  per  square  foot.  A  1-in.  finish 
over  a  6-in.  concrete  base  should,  therefore,  cost  15  to  18  cents 
per  square  foot.  A  cement  base  10  in.  high  and  f  in.  thick 
joining  the  wall  and  floor,  costs  12  cents  per  lineal  foot  in  place 
in  large  amounts,  and  15  to  20  cents  .per  lineal  foot  for  smaller 
quantities,  and  the  labor  cost  of  forming  floor  gutters  is  15  to  20 
cents  per  lineal  foot.  When  this  type  of  floor  is  used  in  a  foun- 
dry, the  finished  wearing  surface  must  be  covered  with  4  in.  of 
moulding  sand. 

Granolithic  Floors. — Granolithic  floors  in  shops  are  not  very 
popular  and  yet  as  they  are  largely  used,  some  rules  are  given 
to  aid  in  securing  the  best  results.  In  order  to  discover  the 
degree  of  favor  with  which  they  have  been  received,  letters  were 
sent  a  year  or  two  ago  to  a  large  number  of  factory  owners,  and 
out  of  forty  replies  received,  twenty-six  expressed  a  decided 
preference  for  wood,  with  only  eight  in  favor  of  granolithic, 
while  the  remaining  six  liked  the  two  kinds  of  floor  equally  well. 
As  the  chief  objection  to  granolithic  floors  is  that  they  rapidly 
convey  heat  away  from  the  body  and  produce  a  feeling  of 
weariness,  it  is  now  an  established  rule  that  these  floors  are 
suitable  only  when  they  are  heated.  This  has  been  successfully 
done  in  several  shops,  as  in  the  plants  of  the  Brown  Hoisting 
Machinery  Company  and  the  Morse  Chain  Company.  When 
these  floors  are  not  heated,  employees  may  wear  shoes  with 
wooden  soles,  as  is  frequently  done  at  metallurgical  works  when 
walking  over  hot  metal,  or  where  the  floors  are  constantly  wet. 

Some  other  disadvantages  of  granolithic  floors  are  that  they 
are  dusty  and  wear  into  ruts  and  hollows,  especially  when 
exposed  to  the  action  of  trucks  and  wheels.  The  tendency  to 
dusting  or  to  disintegration  of  the  surface  is  due  to  a  lack  of 
density,  and  can  be  avoided  by  attending  to  the  directions  for 
laying  granolithic  herein  given.  When  laid  out  in  squares  or 
rectangles  the  granolithic  chips  around  the  edges,  and  for  this 
reason  wheels  should  have  rounded  treads  or  rubber  tires. 
Concrete  is  also  chipped  by  heat,  and  in  conflagrations  it  dis- 
integrates for  a  depth  of  about  half  an  inch  below  the  surface. 

Granolithic  floors  need  experienced  men  to  lay  them,  for  it 
only  requires  a  little  bad  workmanship,  poor  concrete,  insufficient 
cement,  or  some  foreign  substance  such  as  loam,  to  make  the 
floor  a  failure,  and  early  breaks  and  disintegration  a  certainty. 


GROUND  FLOORS  167 

They  are  also  difficult  to  repair,  much  more  so  than  wood,  and 
repairs  occupy  a  longer  time.  They  are  not  suitable  for  shops 
with  edged  tools,  which  are  easily  injured,  and  castings  are 
liable  to  break  by  falling.  In  addition  to  these  objections,  it  is 
difficult  to  attach  machinery  to  granolithic  floors. 

The  merits  of  these  floors  depend  largely  upon  the  care  with 
which  they  are  laid.  They  are  fireproof,  and  are  accepted  as 
waterproof  by  the  New  York  Board  of  Fire  Underwriters.  They 
can  be  washed  off  clean  without  injury  and  are  not  disintegrated 
by  such  usage.  When  properly  laid,  they  are  impervious  to  oil 
and  are  not  injured  by  it,  though  oil  will,  of  course,  enter  cracks 
which  are  large  enough  to  admit  it.  These  floors  are  cheaper 
than  wood  and  when  heated,  as  can  easily  be  affected  in  upper 
stories,  they  no  longer  have  the  objection  of  causing  cold  feet 
and  limbs. 

The  most  approved  mixture  for  granolithic  work  consists  of 
equal  parts  of  cement,  sand,  and  screened  crushed  stone,  from 
a  size  which  will  pass  through  a  20-mesh  up  to  a  maximum  size 
of  %  in.  It  is  important  that  the  crushed  stone  be  screened  to 
remove  the  dust.  Some  cement  users  prefer  to  omit  the  sand 
entirely,  using  only  equal  parts  of  cement  and  screened  crushed 
stone.  It  should  be  mixed  as  dry  as  can  be  worked,  and  put 
down  in  two  layers  with  a  total  thickness  of  about  f  in.,  the 
top  coat  being  put  on  while  the  under  one  is  wet,  so  they  will 
unite.  To  prevent  edge  chipping  and  dust  formation,  the  squares 
should  be  large,  not  less  than  about  20  ft.,  and  where  the  floors 
are  to  be  used  by  horses  for  pulling  loads,  the  surface  should  be 
roughened.  Along  heavy  lines  of  travel,  wheel  plates  of  either 
wrought  or  cast  iron  may  be  set  into  the  floor,  or  a  track  may  be 
made  of  iron  grating  bars  on  edge,  filled  in  between  with  the 
granolithic  mixture.  These  will  prevent  the  floor  from  cracking 
and  supply  horses  with  a  good  foothold.  A  recent  and  rapid 
method  of  surfacing  concrete  floors  is  by  the  use  of  the  cement 
gun  worked  by  compressed  air  which  throws  the  mixture  into 
place  through  a  hose.  It  has  been  successfully  used  by  the 
United  States  Government  and  is  proposed  for  some  large 
buildings  in  Chicago. 

Dust  formation  may  be  avoided  in  several  ways,  the  easiest  of 
which  is  to  give  the  surface  a  hard  troweled  finish.  Dust  may 
also  be  prevented  by  an  occasional  application  of  hot  silicate  of 
soda,  or  a  wash  of  linseed  oil  thinned  with  turpentine  or  naphtha, 


168     ENGINEERING  OF  SHOPS  AND  FACTORIES 

or  by  painting.  A  method  of  preventing  dust  which  is  perhaps 
the  most  effective  of  all,  is  to  cover  the  floor  with  linoleum 
fastened  down  with  glue,  using  1£  gallons  of  glue  per  100  sq. 
ft.  of  floor  surface. 

Granolithic  1|  in.  thick,  when  laid  on  a  moist  or  green  base, 
costs  4^  cents  per  square  foot,  but  when  put  down  after  the 
base  has  hardened,  it  will  cost  about*^  cents. 

The  repairing  of  these  floors  is  also  important,  requiring  the 
services  of  skilled  workmen.  Main  aisles  or  passageways, 
when  they  become  worn,  may  be  reinforced  with  kn  additional 
layer  of  granolithic  over  the  old  one.  Broken  edges  may  be 
repaired  with  a  mixture  of  soft  asphalt,  the  bonding  being  affected 
by  heating  the  injured  surface  with  a  blow  torch.  This  method 
is  better  than  patching  with  cement  paste,  though  not  as  per- 
manent as  the  process  described  later.  The  most  approved 
method  of  repairing  is  to  cut  away  the  granolithic  with  a  sand 
blast  or  with  chisels  to  the  bottom  of  the  break,  until  the  aggre- 
gate is  exposed  enough  to  give  a  bond.  Then  treat  the  surface 
with  acids  and  wash  with  a  hose  to  remove  the  dust,  after  which, 
the  surface  should  be  covered  with  a  thin  grout.  The  new  grano- 
lithic material  should  then  be  applied  while  the  grout  is  still  wet, 
and  the  patch  should  be  kept  protected  and  moist  for  about  a 
week,  when  the  repaired  floor  is  again  ready  for  use. 

Asphalt  Floors. — Asphalt  floors  have  many  commendable 
features,  though  costing  more  than  some  other  kinds.  They  are 
waterproof;  have  no  dust;  are  not  volatile  like*  tar;  are  elastic 
enough  to  prevent  crack  formation;  can  be  kept  clean;  and  are 
comfortable  to  walk  upon.  They  do  not  tire  the  feet  of  workmen 
like  concrete  or  brick  and  do  not  wear  away  but  simply  compress. 
They  are  not  injured  by  frost  or  thaws,  and  should  last  at  least 
ten  years  without  repairs. 

Rock  asphalt  is  limestone  impregnated  with  8  to  17  per  cent, 
bitumen.  It  is  made  into  asphalt  mastic  for  commercial  use, 
by  first  grinding  it  to  a  powder  and  then  heating  it  for  five  hours 
in  a  kettle  at  a  temperature  of  350°  F.  with  8  per  cent,  of  Trinidad 
asphalt  added  to  prevent  its  burning.  It  is  then  moulded  into 
blocks  weighing  50  to  60  lb.,  each  block  having  the  name  of  the 
mine  moulded  thereon.  The  finished  product  contains  14  per 
cent,  of  bitumen  and  86  per  cent,  carbonate  of  lime. 

It  is  prepared  for  floors  by  mixing  it  with  Trinidad  asphalt 
and  sand  in  the  following  proportions  by  weight: 


GROUND  FLOORS  169 

Broken  mastic  blocks 60  per  cent. 

Trinidad  asphalt 4  per  cent. 

Fine  gravel  and  sand 36  per  cent. 

Total 1€0  per  cent. 

The  mixture  is  then  heated  to  a  temperature  of  300  to  400°  F. 
for  about  five  hours  and  constantly  stirred,  after  which  the 
mixture  is  taken  out  and  spread  on  the  floor  to  a  thickness  of 
1  in.  It  is  then  covered  with  sand  and  rubbed  to  a  smooth 
finish.  A  base  for  this  floor  may  consist  of  a  layer  of  concrete 
3  to  4  in.  thick,  or  a  course  of  plank  on  sleepers,  the  plank  being 
overlaid  with  tarred  felt  or  sheathing  paper.  Asphalt  is  also 
moulded  into  paving  blocks  4  by  4  by  12  in.,  and  when  laid  with 
these  blocks,  floors  are  more  easily  repaired. 

Asphalt  has  several  imitations  made  of  tar  and  crushed  lime- 
stone which  are  of  poor  quality,  for  like  other  tar  products,  the 
tar  evaporates  and  the  floor  cracks.  Asphalt  floors  are  not 
suitable  in  shops  where  oil  collects  or  drips,  for  the  asphalt  is 
softened  and  destroyed  by  oil.  A  1-in.  floor  without  the  base 
costs  from  16  to  18  cents  per  square  foot. 

A  substitute  for  asphalt  paving  which  may  be  suitable  also 
for  shop  floors  is  now  extensively  used  on  streets  at  Ann  Arbor, 
and  is  giving  good  service.  Over  a  base  of  4  to  6  in.  of  gravel- 
concrete,  tar  or  bitumen  is  spread,  using  a  half  gallon  per  square 
yard,  and  into  this  is  rolled  a  layer  of  sand  J  in.  thick.  The 
wearing  surface  complete,  costs  only  5  cents  per  square  yard,  and 
the  whole  pavement  about  80  cents  per  square  yard,  with  labor 
at  $2  per  day  and  cement  at  $1  per  barrel. 

Brick  Floors. — A  fine  basement  floor  over  dry  soil  is  made  by 
first  placing  a  12-in.  layer  of  well  compacted  sand  rolled  and 
leveled,  over  which  a  course  of  brick  is  laid  flat,  and  on  this 
another  layer  of  brick  on  edge,  both  courses  being  jointed  with 
cement  mortar  and  grouted  full. 

The  floors  of  foundry  pits  should  have  two  layers  of  brick 
over  a  6-in.  concrete  base,  and  the  pit  walls  should  be  one  brick, 
or  8  in.  thick,  all  laid  in  cement  mortar.  For  boiler  house  floors, 
the  bricks  may  be  laid  flat  with  diagonal  joints,  giving  a  pattern 
effect.  There  is  no  better  floor  for  round  houses  than  brick,  for 
when  injured  they  are  easily  repaired.  The  pressure  of  heavy 
jacks  and  the  rolling  about  of  trucks  and  wheels  have  been  found 
to  cause  frequent  breakage  to  round  house  floors;  and  when  made 
of  brick,  they  can  be  easily  replaced  by  removing  only  a  small 


170     ENGINEERING  OF  SHOPS  AND  FACTORIES 

portion.  Wood  floors  wear  out  too  quickly,  and  concrete 
cracks  and  disintegrates  under  heavy  loads.  A  timber  base 
should  be  avoided,  the  repairing  of  which  would  necessitate  the 
removal  of  a  larger  area. 

The  ground  should  be  excavated  to  a  depth  of  8  in.  and  should 
then  be  well  rammed,  alL  alluvial  soil  being  removed  and  de- 
pressions filled  up  with  sand  and  gravel.  A  4-in.  layer  of  sand 
should  then  be  spread  and  tamped,  after  which  hard  bricks  are 
laid  on  edge.  If  a  waterproof  floor  is  needed,  the  bricks  should  be 
grouted  and  covered  with  tar.  As  slag  and  cinder  usually  costs 
the  railroad  company  nothing,  they  are  frequently  used  as  a  bed 
for  these  pavements  instead  of  sand  and  gravel.  The  floors  of 
engine  pits  should  be  crowned  two  inches  at  the  center  for  drain- 
age, and  the  walls  should  be  capped  with  timber  at  each  side  of 
the  pit.  These  floors  usually  cost  from  85  cents  to  $1.15  per 
square  yard. 

Recommended  Types. — The  types  of  floor  which  have  been 
found  from  experience  to  be  the  best  for  shops  of  different  kinds 
are  given  in  the  following  tabulation: 

Annealing  rooms Brick  or  cast-iron  plates. 

Car  shops  and  car  houses Concrete  base  with  granolithic  finish. 

Cleaning  rooms Cast-iron  plates. 

Cupola  floors Inverted  steel  channels,  rough  rolled  or 

cast-iron  plates. 

Forge  shops Earth  or  cinder  floors. 

Foundry  pouring  floors Cast-iron  plates  or  brick  on  plank  and 

sand. 

Moulding  floors Concrete  or  brick. 

Machine  shops Creosoted  wood  blocks  or  plank  on  con- 
crete base. 

Offices Maple  or  yellow  pine  on  sleepers  over 

concrete. 

Power  house,  Engine  rooms Concrete  with  cement  or  tile  finish. 

Power  house,  Boiler  rooms Concrete  with  cement  or  brick  on  edge. 

Toilets Concrete  with  cement  finish. 

Wash  rooms Concrete  with  cement  surface. 

The  above  are  generally  the  best,  though  in  some  cases,  such 
as  round  houses  and  machine  shops,  preference  and  practice  has 
a  considerable  variation.  Round  house  floors  have  received 
much  attention  from  the  railroad  companies,  and  several  types 
are  extensively  used,  including  cinders  on  clay,  plank,  brick,  and 
concrete.  These  floors  receive  very  hard  usage  from  hydraulic 
jacks  and  the  removal  of  trucks  and  other  paits,  and  a  floor  of 


GROUND  FLOORS  171 

vitrified  paving  brick  is  usually  preferred;  for  as  previously 
stated,  when  damaged,  it  can  easily  be  repaired  by  removing 
only  the  injured  part.  The  repairing  of  timber  or  concrete 
floors  is  more  difficult,  for  a  larger  area  must  be  taken  up.  Wood 
blocks  lack  resistance,  and  when  laid  over  planks,  they  are  sub- 
ject to  the  same  objection  as  other  timber  floors. 

Machine  shop  floors  have  been  the  subject  of  many  experiments. 
They  usually  receive  hard  service,  especially  in  erecting  shops 
where  loads  are  dragged  along  the  floor  by  the  lifting  cranes  and 
machinery  parts  are  piled  up  high,  thus  subjecting  the  floors 
to  heavy  weight.  Brick,  concrete  and  asphalt  conduct  heat  away 
from  human  bodies  and  are,  therefore,  uncomfortable;  and  sharp- 
edged  tools  are  injured  by  falling  on  such  hard  surfaces.  Grit 
and  dust  rising  from  them  are  injurious  to  machines,  especially 
in  the  bearings.  For  these  reasons,  some  kind  of  wood  floor  is 
usually  preferred. 


CHAPTER  XIV 


UPPER  FLOORS 

Slow  Burning  Wood  Floors. — The  essential  principle  of  this 
type  of  construction  is  to  use  the  fewest  number  of  laige  framing 
pieces,  so  that  they  may  not  easily  be  attacked  by  fire.  It  has 
been  well  proven  by  numerous  fires  that  wood  framing  so  ar- 
ranged is  a  better  fire  risk  than  unprotected  steel"  framing,  which 
collapses^quickly  under  heat. 

Beams  should  not  be  closer  than  5  to  10  ft.  apart,  and  the  pro- 
per spacing  may  be  found  from  the  following  table  giving  the 
required  thickness  of  plank  for  various  spans  and  loads. 

TABLE  XV.— SAFE  LOADS  IN  POUNDS  PER  SQUARE  FOOT  FOR  SPRUCE  PLANK 
OF  VARIOUS  SPANS  AND  THICKNESSES,  FOR  LIMITED  DEFLECTIONS 


Sp* 

in  in  f 

eet 

Load  per  square 

foot  superficial 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

30 

0  9 

1  2 

1  4 

1  7 

1  9 

2.1 

2.4 

2.6 

2.8 

3.1 

3.4 

40  

1   i 

1  4 

1  6 

1  9 

2.2 

2.5 

2.8 

3.0 

3.2 

3.5 

3.8 

50  

1  2 

1  5 

1  8 

2  1 

2.4 

2.7 

3.0 

3.3 

3.6 

3.9 

4.2 

75  

1  5 

1  9 

2  3 

2.7 

3.0 

3.4 

3.8 

4.2 

4.5 

5.0 

5.4 

100  

1.7 

2.2 

2.6 

3.0 

3.4 

3.9 

4.4 

4.8 

5.1 

5.6 

•6.0 

125  

1.9 

2.4 

2.9 

3.4 

3.8 

4.3 

4.8 

5.3 

5.7 



150  

2.1 

2.6 

3.1 

3.7 

4.2 

4.7 

5.2 

5.7 

175 

2  3 

2  9 

3  4 

4  0 

4  5 

5  2 

5  8 

200  

2.4 

3.0 

3.6 

4.2 

4.8 

5.4 

6.0 





225  

2.5 

3.1 

3.8 

4.4 

5.1 

5.6 





250 

2  7 

3  3 

4  0 

4  7 

5  4 

6  0 

275          . 

2  8 

3  5 

4  2 

4  9 

5  6 

300 

2  9 

3  6 

4  4 

5  2 

5  9 

305 

3  1 

3  8 

4  6 

5  4 

6  1 

350  

3.2 

4.0 

4.8 

5.6 

375  

3.3 

4.2 

5.0 

5.8 



400  

3.4 

4.3 

5.1 

6.0 



Plank  when  laid  flat,  should,  for  thicknesses  of  2f  in.  or 
less  have  tongue  and  groove,  and  for  greater  thicknesses  should 
for  economy  be  connected  by  splines.  An  excellent  solid  floor 
is  obtained  by  placing  boards  on  edge,  and  spiking  them  together, 

172 


UPPER  FLOORS  173 

the  upper  surface  being  covered  with  1/2-in.  tar  mortar  before 
laying  the  top  course  of  boards. 

The  mortar  should  consist  of  one  part  of  tar  with  two  parts  of 
sand.  The  extra  strength  of  continuity  is  secured  by  staggering 
the  board  joints,  preferably  at  the  point  of  contra  flexure,  about 
one  quarter  way  between  the  bearings.  The  best  material  for 
wood  beams  is  hard  or  yellow  pine.  The  lower  corners  should  be 
champfered,  and  in  brick  walls,  beams  should  have  cast-iron  bear- 
ing plates  with  flanges,  one  to  anchor  them  to  the  masonry,  and 
another  fitted  into  the  beam.  The  upper  end  of  the  beams  above 
the  bearings  should  be  mitred,  to  prevent  inner  leverage  on  the 
wall,  in  case  the  beams  collapse  by  fire. 

Wood  floors  should  always  have  an  upper  wearing  surface 
which  can  be  removed  as  often  as  it  becomes  worn.  Yellow  pine 
is  the  best,  though  maple  and  oak  are  sometimes  used.  The 
edges  were'  formerly  matched  or  tongue  and  grooved,  but  owing 
to  the  difficulty  of  replacing  this  kind  of  floor,  and  its  liability  to 
splitting  at  the  edge  under  trucks  or  other  loads,  square-edged 
flooring  is  now  preferred.  A  thickness  of  f  in.  is  quite  as  good 
as  1J  in.,  for  when  the  floor  is  worn  enough  to  need  renewal 
of  the  thinner  boards,  the  thicker  board  would  also  have  needed 
renewal. 

In  order  to  prevent  water  from  leaking  through  the  floor,  there 
should  be  two  or  three  layers  of  tar  or  rosin  paper  between  the 
upper  and  lower  courses,  and  the  last  layer  of  paper  should  pre- 
ferably be  mopped  with  tar.  Asbestos  paper  for  this  purpose 
has  the  additional  advantage  of  being  fireproof.  Wood  must 
remain  unpainted  until  the  timber  is  thoroughly  seasoned,  for 
if  applied  too  soon,  it  only  promotes  decay. 

The  cost  of  wood  floors  with  f-in.  maple  over  3-in.  plank  on 
8  by  12-in.  yellow  pine,  6  ft.  apart,  is  as  follows: 

Wood  beams . . : $  6 . 50  per  square 

Iron  stirrups 3 . 00  per  square 

Anchors 2 . 50  per  square 

3-in.  plank 12 . 00  per  square 

Paper 50  per  square 

Factory  maple  flooring 7 . 00  per  square 


Total $31 . 50  per  square 

The  Sessions  Foundry  at  Bristol,  Conn,  has  3-in.  tongue  and 
groove  yellow  pine  on  12  by  18-in.  yellow  pine  beams,  while  a 


174     ENGINEERING  OF  SHOPS  AND  FACTORIES 

gallery  floor  in  the  Granger  Foundry  at  Providence,  designed  by 
the  writer,  has  a  double  wood  floor  on  8  by  12-in.  beams  only  5 
ft.  apart,  supported  on  12-in.  steel  beams. 

These  floors  should  be  protected  against  fire  by  an  adequate 
sprinkling  system. 

Wood  Floors  with  Steel  Beams. — -A  low  cost  wood  floor  which 
is  lacking  in  fire  resisting  qualities,  is  made  by  placing  heavy 
wood  joists  say  3  by  16  in.,  16  to  20  in.  apart — which  are  sup- 
ported on  steel  beams  or  riveted  girders  10  to  15  ft.  on  centers. 
The  cost  of  wood  work  in  the  floor,  with  two  fayers  of  pine,  J 
and  2J  in.  is  12  to  15  cents  per  square  foot  erected,  not  in- 
cluding any  steel. 

As  framing  timber  is  becoming  more  scarce  every  year,  steel 
joists  are  often  used  instead  of  wood,  and  this  type  is  now  ac- 
cepted by  the  insurance  companies  as  a  substitute  for  slow 
burning  wood  construction.  Beam  spacing  in  this  type  can  be 
reduced  to  3  or  4  ft.  with  a  corresponding  reduction  in  the 
thickness  of  plank.  The  steel  joists  are  capped  with  wood 
spiking  pieces,  about  4  by  5  in.,  which  are  hook  bolted  to  the 
beams.  The  beams  may  be  protected  from  fire  by  a  suspended 
ceiling  of  expanded  metal  and  plaster,  and  if  extra  fire  precaution 
is  needed,  an  upper  wearing  surface  of  asphalt  may  be  used  in- 
stead of  wood.  Suspended  ceilings  are  only  a  partial  protection, 
for  in  great  conflagrations,  such  as  at  San  Francisco,  it  was  found 
that  these  ceilings  break. 

Triangular  Sheet  Steel  Floor  (Buckeye). — Several  forms  of 
sheet  metal  trough  floors  are  available,  most  of  them  having  the 
merit  of  maximum  stiffness  for  the  amount  of  material  used.  One 
of  these,  made  in  Ohio  and  known  as  the  Buckeye  floor,  has  metal 
trough  24  in.  deep,  and  including  the  concrete  filling  and  1J 
in.  wearing  surface,  weighs  about  35  Ib.  per  square  foot. 

WEIGHT     OF     GALVANIZED     TRIANGULAR     TROUGH     FLOORING,    2*    IN. 
DEEP,  IN   POUNDS  PER  100  SQ.  FT. 

Gauge 

No.  16 386  Ib.  per  square 

18 313  Ib.  per  square 

20 241  Ib.  per  square 

22 204  Ib.  per  square 

24 168  Ib.  per  square 

The  sheets  are  made  in  lengths  up  to  10  ft.  and  in  uniform 
widths  of  21  in. 


UPPER  FLOORS 


175 


Multiplex  Floor. — Another  excellent  sheet  metal  trough  floor 
is  that  known  as  the  Multiplex.  The  troughs  are  made  of  2  in. 
uniform  width,  and  depth  of  2,  2^,  3  and  4  in.  either  painted  or 
galvanized.  Stock  lengths  vary  anywhere  from  5  to  10  ft.,  and 
gauge  from  No.  16  to  No.  24.  They  are  laid  directly  on  the  floor 
beams  and  are  filled  with  concrete  to  a  depth  of  2  in.  above  the 
metal,  but  cannot  be  plastered  on  the  under  side  and  must  be 
kept  painted.  If  a  wood  wearing  surface  is  desired,  wood  nailing 
strips  must  be  embedded  in  the  concrete  above  the  metal,  or 
these  may  be  omitted,  and  a  granolithic  surface  used  instead. 


TABLE  XVI.— SAFE  LOADS  ON  MULTIPLEX  STEEL  FLOORS  WITH  CONCRETE 
FILLING  1  IN.  ABOVE  THE  METAL 


Metal  gauge 

Depth 

Weight 

4ft. 

6ft. 

8ft. 

10ft. 

20 
24 

4 

18 
17.3 

1260 
792 

550 
352 

300 
198 

185 
127 

20 
24 

a* 

17.5 
16 

1115 
720 

485 
320 

265 
180 

165 
115 

20 
24 

3 

15.3 
14.0 

970 
550 

420 
244 

230 
137 

145 

88 

20 
24 

2£ 

13.4 
12.2 

675 
433  x 

295 
192 

160 
108 

100 
69 

Metal  Arches. — Arches  of  stiffened  sheet  metal  between  steel 
beams  with  concrete  filling  above  them,  are  extensively  used. 
They  have  the  objection  common  to  all  kinds  of  exposed  metal, 
that  they  must  be  kept  painted,  or  they  will  be  destroyed  by 
rust.  No.  18  gauge  corrugated  iron  with  a  10-in.  rise,  between 
beams  6  ft.  apart,  has  been  tested  with  a  load  of  1000  Ib.  per 
square  foot,  and  for  beam  spacing  of  9  ft,  with  3  in.  of  concrete 
over  the  metal  at  the  center,  it  will  safely  carry  a  load  of  200  Ib. 
per  square  foot.  The  strength  of  this  floor  can  be  increased  by 
making  a  greater  crown  thickness  of  concrete.  It  is,  therefore, 
strong,  apart  from  the  filling  above  it,  which,  for  the  sake  of 
lightness,  is  sometimes  made  of  cinders.  If  cement  and  stone 
concrete  is  used  instead  of  cinders,  the  strength  is  greatly  in- 


176     ENGINEERING  OF  SHOPS  AND  FACTORIES 

creased.  A  floor  of  this  kind  in  an  engine  house  designed  by  the 
writer  cost  56  cents  per  square  foot  in  place.  Dovetailed  metal 
is  sometimes  used  instead  of  corrugated  iron,  with  the  false  impres- 
sion that  it  can  safely  be  plastered  on  the  under  side.  This 
product  offers  insufficient  grip  to  hold  plaster,  for  a  large  building 
in  which  it  was  thus  used  .was  inspected  by  the  writer  after  the 
plaster  had  fallen.  The  fall  of  so  much  heavy  material  not  only 
injured  the  machinery,  and  other  contents  of  the  building  but 
also  endangered  the  lives  of  the  workmen.  No.  24  gauge 
dovetailed  sheets  cost  $8  to  $10  per  100  sq.  ft.  sCt  the  place  of 
manufacture,  and  weigh  163  Ib. 

Metal  Trough  Floors. — A  much  stronger  and  heavier  metal 
floor  is  obtained  by  using  troughs  made  of  rolled  shapes  riveted 
together.  These  are  more  used  for  very  heavy  service  as  on 
bridge  floors,  but  are  occasionally  appropriate  in  buildings,  the 
office  of  the  Pencoyd  Iron  Works,  having  several  floors,  made  of 
Lindsay  troughs  painted  a  light  blue  on  the  under  side.  Floor 
sections  made  with  sloping  sides  are  liable  to  vary  slightly  in 
width  when  riveted,  and  it  is,  therefore,  difficult  to  match  the 
connecting  holes  in  the  supporting  girders.  For  this  reason, 
vertical  sides  are  generally  preferred.  To  economize  in  head 
room,  the  sections  should  rest  on  shelf  angles,  fastened  to  the 
girder  webs  rather  than  bearing  on  their  upper  flanges.  Vertical 
troughs  in  small  sizes  are  most  conveniently  made  of  Z's  and 
plates,  but  for  greater  depths  they  are  composed  of  plates  and 
angles.  Floor  troughs  vary  in  weight  from  15  to  40  Ib.  per  square 
foot,  and  tables  of  safe  loads  may  be  found  in  the  handbook  of 
the  Carnegie  Steel  Company. 

Plate  Floors. — Cast-iron  or  rolled-steel  plates  roughened  on  the 
upper  side  are  much  used  in  certain  places  exposed  to  fire,  such 
as  cupola  floors,  or  around  furnace  openings.  Rolled  steel 
plates  are  made  in  thicknesses  of  T5e-  in.  to  £  in.,  weighing 
13.8  to  21.4  Ib.  per  square  foot.  Cast-iron  plates  can  be  made 
heavier  and  stiffer  than  rolled  ones  and  can  be  roughened  enough 
on  the  surface  to  prevent  men  from  slipping.  They  are  exten- 
sively used  in  foundries  and  for  charging  floors. 

Brick  Arch  Floors. — Brick  or  terra  cotta  arch  floors  are  heavy 
and  expensive  and  not  well  suited  to  factory  buildings  subject 
to  jars  and  vibrations.  The  movement  of  heavy  machines  is 
liable  to  loosen  the  bricks  and  cause  them  to  fall  Brick  arches 
are  laid  in  single  rings  4  in.  thick  on  temporary  wooden  forms, 


UPPER  FLOORS  177 

the  distance  between  beams  not  exceeding  4  to  5  ft.,  and  the 
arch  rise  at  least  one-eighth  of  the  span.  The  filling  and  floor 
above  the  arch  may  be  similar  to  that  used  in  other  arch  forms, 
and  concrete  may  be  used  for  filling,  with  a  finish  either  of  wood 
boards  on  nailing  strips,  or  granolithic. 


12 


CHAPTER  ^ 
CONCRETE  UPPER  FLOORS 

Concrete  floors  are  of  three  general  kinds. 

1.  Those  without  slabs  but  with  concrete  beams  and  wood 
floors. 

2.  Those  with  concrete  beams  and  sjabs. 

3.  Those  with  flat  concrete  slabs  only,  supported  directly  on 
columns. 

The  first  of  these  types  with  no  slabs  but  with  concrete  beams 
supporting  a  double  layer  of  floor  planks  (Fig.  79)  is  very  eco- 
nomical in  cost.  It  is  also  lighter  than  a  concrete  floor,  for  while 
this  material  weighs  140  Ib.  per  cubic  foot,  wood  does  not  exceed 
50  Ib.  A  four-story  concrete  office  building  in  Massachusetts, 
with  T-beams  without  slabs  and  two  layers  of  wood  floor,  cost 
with  the  equipment  of  lighting,  heating,  toilets  and  partitions 
only  9.2  cents  per  cubic  foot,  or  $1.30  per  square  foot  of  floor 
area.  Without  equipment,  the  cost  including  foundation,  walls, 
floors  and  roofs,  was  only  4J  cents  per  cubic  foot,  or  $0.63  per 
square  foot  of  floor  area.  Wood  nailing  pieces  were  secured  to 
each  side  of  the  concrete  beams,  and  between  it  and  the  lower 
course  of  plank  was  a  thin  filling  of  cinders.  A  five-story  con- 
crete factory  in  the  same  state,  50  ft.  wide  and  300  ft.  long,  of 
the  same  general  type  as  the  last,  cost  without  equipment,  only 
7.6  cents  per  cubic  foot,  with  a  total  saving  of  $24,000  over  a 
concrete  design  with  beams  and  slabs. 

A  floor  of  the  same  type  in  a  knitting  mill  in  the  central  part 
of  New  York  state,  cost: 

2-in.  hemlock  plank $.07    per  square  foot 

Deadening  felt 005  per  square  foot 

7/8-in.  floor  and  finish 09    per  square  foot 

Plaster  board 025  per  square  foot 


Total $ .  19    per  square  foot 

For  the  same  place  a  floor  with  reinforced  concrete  slab  and 
wood  top,  would  have  cost: 

178 


CONCRETE  UPPER  FLOORS 

Reinforced  concrete  slab $ .  40  per  square  foot 

Nailing  strips  in  place 03  per  square  foot 

Upper  floor,  finished 09  per  square  foot 

Plaster  under 04  per  square  foot 


179 


Total $ .  56  per  square  foot 

or  about  three  times  as  much  as  that  used. 

Generally,  concrete  buildings  with  timber  floors  but  without 
any  slab,  cost  15  to  25  per  cent,  less  than  when  a  slab  is  used, 
and  they  cost  less  than  wood  mill  construction. 

Floors  with  Beams  and  Slabs. — This  type  constitutes  by  far  the 


Bridging  Joist 


Mould  for  Bottom  of  Girder 

FIG.  85. — Metal  covered,  wood  form  boxes. 

largest  class  of  floors  in  concrete  .buildings.  Apart  from  shop- 
made  floor  sections  and  joists,  which  have  previously  been 
described  under  " Separately  Moulded  Members"  there  are 


FIG.  85a. — Steel  forms  for  concrete  floors. 

many  systems  of  monolithic  beam  and  slab  construction.  A 
type  which  is  qute  economical  is  that  used  in  buildings  for 
the  University  of  Wisconsin.  For  the  purpose  of  forming  ribs, 
inverted  boxes  were  used  instead  of  the  usual  forms,  and  they 
were  so  arranged  as  to  make  a  system  of  inverted  beams  and 
joists,  Fig.  85.  These  boxes  were  covered  with  sheet  metal  and 
were  used  thirty  times  or  more.  The  total  floor  area  in  one 
building  was  4500  sq.  ft.,  and  provision  was  made  for  a  live 


180     ENGINEERING  OF  SHOPS  AND  FACTORIES 


load  of  200  Ib.  per  square  foot.     The  itemized  cost  of  floors  in 
this  building,  per  square  foot  of  floor  was  as  follows: 


Concrete 

Reinforcing  steel 

Timber  for  supports 

Wood  boxes,  1/15  of  cost 

Erecting  supports  and  boxes :. 

Placing  concrete  and  reinforcement . 
Removing  supports  and  boxes 

Total . . 


10 . 54  cents 
7 . 86  cents 
6 . 60  cents 
.72  cents 
5 . 54  cents 
4.44  cents 
1 . 10  cents 


per  square  foot 
per  square  foot 
per  square  foot 
per  square  foot 
per  square  foot 
per  square  foot 
per  square  foot 


,  36 . 80  cents  per  square  foot 


A  system  of  beams  placed  close  together,  with  sloping  sides, 
forming  a  heavy  ribbed  slab  (Fig.  86),  was  used  in  the  balcony 
floor  of  a  machine  shop  for  the  Fairbank-Morse  Company  at 
Toronto,  Canada.  The  beams  were  22  in.  wide  at  the  top  and 

K 3'o" ->i  „  ,,„   ,      L-  //?';..-J 


Section    of    Balcony    F'oor 


2.  Stirrups  -:;' 


15,  g  Rods 


Section  of  Roof  Girder 


530' 


-1000" 


FIG.  86. — Machine  shop  of  Fairbanks-Morse  plant,  Toronto,  Canada. 

6  in.  at  the  bottom,  and  were  placed  3  ft.  apart  on  centers, 
each  beam  being  reinforced  with  six  rods,  \\  in.  in  diameter. 
A  roof  over  the  gallery  was  of  the  same  general  type  with  a  3-in. 
slab  on  beams  of  the  same  size  placed  8  ft.  apart.  The  tendency, 
however,  in  recent  years  is  to  use  heavier  slabs  and  fewer  beams, 
and^it  is  now  common  to  find  beams  16  to  20  ft.  apart,  at  the 
columns  only,  without  intermediate  joists. 

Slabs  may  be  supported  at  all  four  sides  or  at  two  sides  only, 


CONCRETE  UPPER  FLOORS  181 

the  first^bemg]  the  strongest  and  most  economical  arrangement. 
With  four  side  supports,  the  reinforcing  steel  will  lie  in  two  direc- 
tions at  right  angles  to  each  other,  and  for  economy,  the  slabs 
should  be  continuous  over  their  supports.  Another  economical 
plan  is  to  use  slabs  8  to  12  ft.  long,  supported  on  lines  of  beams 
resting  directly  on  the  columns  without  joists  or  cross  girders. 
Roof  framing  is  usually  made  of  the  same  dimensions  as  the 
floors,  for  extra  stories  can  then  be  added  if  desired  without 
removing  the  roof  or  strengthening  it.  In  some  cases,  however, 
as  in  the  machine  shop  at  Toronto,  mentioned  above,  the  roof 
framing  is  made  lighter  than  the  floor. 

Wire  mesh  or  expanded  metal  is  more  convenient  for  slab 
reinforcement  than  loose  bars,  for  it  is  made  at  a  factory  and  can 
be  spread  out  in  sheets.  No.  10  gauge  expanded  metal  with 
4-in.  mesh  is  often  used  and  costs  $3.50  per  100  sq.  ft.  Rein- 
forcing metal  in  slabs  generally  costs  3J  to  4J  cents  per 
square  foot  of  floors  when  designed  for  a  live  load  of  100  Ib.  per 
foot.  Wire  is  economical  because  of  its  high  tensile  strength. 
Triangular  mesh  with  strands  of  No.  4  wire  4J  in.  apart, 
united  by  a  weave  of  lighter  wire  weighs  57  Ib.  per  100  sq.  ft. 
and  costs  $2.30  at  the  mill.  It  is  shipped  in  rolls  up  to  58  in.  in 
width  and  600  ft.  in  length. 

Concrete  slabs  may  have  wearing  surfaces  of  granolithic, 
boards  or  asphalt.  A  granolithic  surface,  as  previously  described 
under  "  Ground  Floors,  "  is  by  far  the  cheapest  though  uncomfort- 
able to  walk  upon.  When  a  wood  floor  is  laid  over  a  concrete 

i\  Maple 


* *  Reinforced  Concrete  * * 


FIG.  87. 

slab,  the  slab  should  first  be  covered  with  two  layers  of  tar  felt 
or  heavy  paper  in  pitch,  or  the  lower  course  of  plank  may  be 
bedded  on  tarred  sand  as  was  done  in  the  Blake  and  Johnson 
factory  at  Waterbury,  Conn.  A  shop  at  Woonsocket,  de- 
signed by  Mr.  F.  W.  Dean,  has  nailing  strips  built  into  the  6-in. 
concrete  slab,  and  to  this  is  spiked  a  lower  course  of  3-in.  plank 
which  is  covered  with  J-in.  maple  (Fig.  87).  The  screeds 


182     ENGINEERING  OF  SHOPS  AND  FACTORIES 

should  be  creosoted  or  coated  with  tar  to  prevent  dry  rot.  An 
upper  layer  1  in.  thick  of  sawdust  concrete  into  which  nails  can 
be  driven,  has  sometimes  been  placed  over  the  lower  slab  and 
beneath  the  floor  boards.  It  should  be  made  of  equal  parts 
by  volume  of  cement  and  sawdust  with  two  parts  of  sand. 

Matched  factory  maple  flooring  J  in.  thick  over  2-in.  spruce 
costs  13  cents  per  square  foot,  anct  f-in.  yellow  pine  over  2-in. 
spruce  costs  9  cents  per  square  foot.  Nailing  strips  or  sleepers 
cost  4  cents  per  lineal  foot  in  place,  and  2-  to  3-in.  cinder  fill 
between  the  strips  costs  3  to  4  cents  per  square4  foot. 

An  asphalt  wearing  surface  is  both  lighter  and  cheaper  than 
wood.  The  concrete  should  first  be  washed  with  a  mixture  of 
melted  tar  and  asphalt  having  just  enough  asphalt  to  make  it 
hard  when  cold.  The  asphalt  should  be  spread  1  in.  thick  and 
rubbed  smooth  with  sand,  as  described  under  "  Ground  Floors." 
A  car  shed  at  Jersey  City,  designed  by  Mr.  J.  B.  French, 
has  a  4-in.  roof  slab  of  cinder  concrete,  reinforced  with  No.  23 
triangular  mesh. 

Original  and  simple  formulae  for  proportioning  concrete  slabs 
are  given  herewith: 


D- 

Miooo 


Where  D  is  the  depth  of  slab  in  inches  from  the  upper  surface  to 

the  center  of  the  rods 

M  is  the  bending  moment  in  inch  pounds  per  foot  width  of  slab 
A,  the  area  of  steel  in  square  inches  per  foot  of  width  (Fig.  88). 


FIG.  88. 

The  weight  of  various  concrete  floor  systems  varies  from  60 
to  120  Ib.  per  square  foot,  including  the  steel,  which  for  the  floor 
only,  is  from  2J  to  6  Ib.  per  square  foot.  Dry  cinder  concrete 
weighs  from  50  to  75  Ib.  per  cubic  foot.  The  weight  of  floors 
depends,  therefore,  on  the  system  used,  the  kind  of  material  and 
their  carrying  capacity. 


CONCRETE  UPPER  FLOORS  183 

The  cost  of  reinforced  concrete  floors  and  framing,  under 
average  conditions,  is  about  as  follows: 

Floor  slabs  and  beams  without  columns  35  to  45  cents  per  square  foot  of 

floor. 

Complete  reinforced  concrete  frames  without  walls  50  to  65  cents  per  square 
foot  of  floor. 

Labor  of  mixing  and  placing  concrete  $1.00  to  $1 .50  per  cubic  yard. 
Total  cost  of  concrete  in  place  $6.00  per  cubic  yard. 
Total  cost  of  concrete  in  place  including  steel  $12.00  per  cubic  yard. 
Forms  and  scaffolding  $5.00  per  cubic  yard. 
Total  cost  of  concrete,  steel  and  forms,  $17.00  per  cubic  yard. 
Cinder  filling  3  in.  thick  over  slabs,  4  cents  per  square  foot. 
Cinder  filling  1|  to  2  in.  thick,  3  cents  per  square  foot. 
Forms,  5  cents  per  square  foot. 
Or  including  beams,  10  to  12  cents  per  square  foot. 

Plain  rods  cost  $30  per  ton  while  patent  or  deformed  ones 
usually  sell  for  $40  to  $45  per  ton. 

The  comparative  cost  of  wood  and  reinforced  concrete  floors, 
with  columns  16  to  18  ft.  apart,  as  determined  by  the  writer, 
showed  that  double  wood  floors  on  fireproofed  steel  beams,  cost 
about  18  cents  per  square  foot  including  the  beams.  Reinforced 
concrete  beam  and  slab  floors  with  granolithic  finish  cost  from 
25  to  30  cents  per  square  foot,  while  concrete  slabs  with  wood 
wearing  surface  will  cost  12  to  15  cents  per  square  foot  additional. 
The  concrete  in  the  floors  of  a  large  building  at  Kansas  City  was, 
in  1908,  laid  at  the  rate  of  50  cu.  ft.  per  man  per  day.  Under 
less  efficient  management,  it  had  formerly  been  placed  at  only 
half  that  rate. 

Flat  Slab  Floors. — Concrete  floors  with  flat  ceilings  have  some 
advantages  over  those  which  have  exposed  ribs  or  beams  under- 
neath them,  because  in  case  of  fire,  jets  of  water  from  fire  hose 
or  sprinkler  systems  are  less  obstructed  on  flat  ceilings  than  when 
beams  are  used,  and  light  is  also  better  diffused.  Shafting  and 
sprinkler  heads  are  more  easily  attached  to  flat  surfaces  than  to 
those  broken  up  with  beams,  the  saving  in  these  items  amounting 
in  some  cases  to  25  per  cent,  of  the  cost  of  installation.  Forms  or 
false  work  for  flat  ceilings  cost  5  to  8  cents  less  per  square  foot 
when  beams  are  omitted.  A  flat  surface  can,  of  course,  be 
affected  by  suspending  a  ceiling  of  expanded  metal  and  plaster 
below  the  floor  beams,  but  this  not  only  incurs  extra  expense  for 
the  ceiling  itself,  but  it  is  no  saving  either  in  the  height  of  the 
building  or  in  the  cost  of  forms.  Another  common  method  is  that 


184     ENGINEERING  OF  SHOPS  AND  FACTORIES 

in  which  hollow  terra  cotta  tiles  are  placed  between  floor  joists 
(Fig.  89)  with  comparatively  close  spacing.  While  this  method 
reduces  the  cost  of  centering,  it  saves  nothing  in  the  floor  thick- 
ness and  includes  the  additional  cost  of  tiles.  Besides,  the  tiles 
are  liable  to  crack  and  fall  from  the  jars  and  vibration  of  machin- 
ery, exposing  the  building  contents  and  the  workmen  to  danger. 
Floors  with  solid  slabs  without  belims  have  a  less  total  thick- 
ness than  the  combined  depth  of  slab  and  beams,  and  the 
available  head  room  in  a  story  is  correspondingly  greater;  or  if  a 
fixed  clear-story  height  is  needed,  the  total  height  of  a  building 
with  flat  slabs  can  be  less  than  with  slabs  and  beams.  In  a  ten- 
story  building  with  beams  16  in.  deep,  the  total  saving  in  the 
building  height  by  using  slab  floors  would  be  from  10  to  12  ft. 


CH  CD 


CD 


c 

d 


FIG.  89. 

The  chief  objection  to  solid  slabs  supported  directly  on 
columns  without  beams  is  their  uncertain  stress  conditions. 
For  fifty  years  or  more  structural  engineers  have  wrestled  with 
the  problems  of  uncertain  stress.  The  merits  of  continuous 
girders,  multiple  truss  systems  and  other  uncertain  types,  have 
long  been  appreciated,  and  yet  the  uncertainty  of  their  stresses 
has  gradually  but  surely  caused  nearly  all  such  systems  to 
be  discarded.  One  of  these  flat  slab  systems  with  the  floor  sup- 
ported by  bars  radiating  from  the  column  tops  at  the  four  corners 
is  suitable  for  column  spacing  not  exceeding  20  ft.  Floor  panels 
16  ft.  square  with  a  7J-in.  rough  slab  not  including  the  If- 
in.  strip  filling  will  sustain  a  safe  test  of  800  Ib.  per  square  foot. 
Larger  panels,  17  ft.  square,  with  a  rough  slab  thickness  of  9J 
in.  and  a  concrete  unit  stress  of  800  Ib.  per  square  inch,  is 
strong  enough  for  a  live  load  of  250  Ib.  per  square  foot,  with 
1J  per  cent,  of  steel  reinforcement  at  the  top  and  bottom  of 
the  slab.  If  1J  per  cent,  of  steel  is  used  at  the  top  only,  the 
required  thickness  of  rough  slab  would  then  be  12  in.  This 
type  requires  about  40  per  cent,  more  steel  than  floors  with 
beams  and  thinner  slabs,  but  the  difference  is  partly  offset  by 
the  lower  cost  of  centering. 


CONCRETE  UPPER  FLOORS 


185 


TABLE  XVII.— THICKNESS  OF  FLAT  REINFORCED  CONCRETE  FLOOR  SLABS 
SUPPORTED  AT  THE  FOUR  CORNERS  ONLY 


Span,  feet 

Total  load  per 
square  foot, 
pounds 

Slab  thickness, 
inches 

(  100 

4 

12 

|  300 

6 

(  500 

7| 

f  100 

4 

14 

\  300 

6J 

[  500 

7| 

* 

r  100 

5 

16 

\  300 

7 

(  500 

8 

f  100 

5* 

18 

<  300 

7^ 

(  500 

9 

f  100 

6 

20 

|  300 

8 

[  500 

10 

r  100 

7 

25 

|  300 

10 

(  500 

11 

In  order  to  determine  the  comparative  cost  of  reinforced 
concrete  buildings  with  flat  slab  floors,  and  with  floors  of  com- 
bined beams  and  slabs,  estimates  were  made  on  a  ten-story 
building  109  ft.  wide  and  580  ft.  long,  which  showed  that  the 
design  with  flat  floor  slabs,  including  a  patent  royalty  of  1J 
per  cent.,  had  a  cost  only  2  per  cent,  less  than  the  design  with 
slabs  and  beams. 

The  itemized  cost  of  concrete  per  cubic  yard,  of  1-2-4  mixture, 
was  as  follows: 

Concrete,  If  barrels  at  $1 . 10 $1 .80 

Sand,  £  yard ' 40 

Stone,  1  yard 1 .00 

Labor 1.00 

Sundries 10 

Total..  .   $4.30 


186     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Concrete  in  columns  had  an  additional  cost  for  labor  of  70  cents 
per  cubic  yard. 

It  is  well  known  that  flat  slabs  supported  only  by  columns  at 
the  four  corners  are  not  subject  to  exact  analysis  and  are  pro- 


I 


Typical 
Section 

I      Girder  Beam  and 
I          Slab  Design 


Typical  Section; 
Paneled-Floor  Construction  Girder,  Beam  and  Slab  Design 

FIG.  90. — Paneled  ceiling,  compared  with  beam  and  slab  design  for  Stude- 
baker  Co.  building,  Chicago. 

portioned  chiefly  from  experiments,  though  the  slabs  are  some- 
times assumed  to  act  as  cantilevers  from  the  flaring  column 
heads.  This  condition  in  itself  should  give  the  preference  to 
other  and  better  forms  which  can  be  proportioned  with  certainty. 
Fortunately  such  forms  are  available,  for  slabs  with  reinforce- 
ment in  two  directions  may  be  supported  on  other  wide  and 


CONCRETE  UPPER  FLOORS  187 

shallow  slabs  or  beams  continuous  over  the  columns,  forming 
large  panels  in  the  ceiling,  corresponding  with  the  position  of  the 
columns.  The  esthetic  effect  of  these  panels  is  much  superior 
to  a  wholly  flat  surface,  and  the  type  is  by  far  the  best  yet 
available  (Fig.  90).  In  the  Sharpless  Building  in  Chicago 
designed  by  Mr.  T.  L.  Condron,  with  columns  about  18  ft.  apart, 
the  main  beams  are  6  ft.  wide  and  only  1  ft.  deep,  with  an  8-in. 
intermediate  slab,  the  weight  of  steel  in  the  floor  being  5J  Ib. 
per  square  foot.  Columns  have  a  uniform  diameter  of  2  ft. 
from  the  basement  to  the  tenth  floor,  the  column  caps  under 
each  floor  having  a  diameter  of  4  ft.  A  similar  arrangement  is 
used  in  the  Studebaker  Building  in  Chicago  in  which  the  columns 
are  24  ft.  apart. 


CHAPTER  XVI 
WALLS,  PARTITIONS  AND  OPENINGS 

Brick  Walls. — Brick  continues  to  be  a  favorite  type  for  the 
outside  walls  of  shops  and  factory  buildings,  because  of  its  neat 
appearance.  It  may  be  used  for  the  whole  exterior  wall,  or  as  a 
veneer  over  the  concrete  structural  parts.  Solid  brick  walls  are 
laid  with  English  or  Flemish  bond,  and  the  bricks  should  be  wet 
before  laying  to  prevent  the  extraction  of  water  from  the 


FIG.  91. — Hollow  concrete  tile  walls.     Hunter  Illuminated  Car  Sign  Co., 
Flushing,  Long  Island. 

mortar.  About  one-fifth  of  brick  walls  is  composed  of  mortar, 
which  should  be  made  by  mixing  one  barrel  of  lime,  four  of  sand, 
and  one-half  barrel  of  cement,  with  one  and  a  half  barrels  of 
water.  When  laid  up  in  courses,  brickwork  will  settle  about 
1  in.  for  every  50  ft.  in  height.  One  man  can  lay  1000  to  1200 

188 


WALLS,  PARTITIONS  AND  OPENINGS  189 

bricks  per  day  in  plain  walls,  and  4000  to  5000  per  day  in  massive 
blocks  such  as  engine  beds  or  foundations.  Doors  and  window 
frames  should  be  made  of  the  proper  size  to  suit  the  brick  courses 
without  cutting.  Brick  walls,  either  8  or  12  in.  thick,  cost  about 
the  same — 45  cents  per  superficial  foot — for  the  material  saved 
in  the  8-in.  wall  is  offset  by  the  greater  labor  cost  of  laying  it. 

Vitrified  Tile  Walls. — Walls  of  vitrified  tile  are  light  and  do 
not  absorb  water.  Blocks  are  usually  8  by  12  by  18  in.,  and 
when  laid  in  the  wall  cost  25  cents  per  superficial  foot,  or  38 
cents  when  plastered  on  both  sides  (Fig.  91). 

Concrete  Block  Walls. — Concrete  blocks  have  a  light  weight 
and  low  cost,  but  have  the  objection  of  being  rather  porous. 
When  the  regulations  of  labor  unions  are  such  as  to  require  the 


FIG.  92. — Hollow  concrete  block  wall. 

employment  of  union  masons  or  bricklayers  for  placing  them, 
the  cost  of  this  kind  of  wall  will  be  increased.  A  recent  type 
is  shown  in  Fig.  92. 

Walls  may  also  be  made  of  8-in.  hollow  concrete  tile  blocks 
8  by  8  by  16  in.,  with  cement  and  aggregate  mixed  in  the  pro- 
portion of  1  to  3.  Stones  in  aggregate  should  not  exceed  5 /8-in. 
diameter.  The  cost  of  laying  these  tiles  with  common  labor  is 
only  about  one-third  that  of  laying  brick  and  the  final  cost  of 


i|rr i; 4riitfrii|  MI •  •  ills*  H 1 1 ing*  ji i ii igw  inn-:  i •  MI  11155  •  •  •••K  •••fie 
r;  um  r;  iiiiip  IIIIIR  11111?;  iiiii^  iiiit!*?  •••••!»?  •••••!•> 

'      '' 


FIG.  93. — Building  with  concrete  block  walls. 

the  finished  walls  has  been  found  to  be  only  40  to  75  per  cent. 
as  much  as  ordinary  brick  and  25  to  50  per  cent,  as  much  as  cut 
stone  or  face  brick  (Fig.  93) . 

Cement  Brick  Walls. — Cement  brick  was  successfully  used  by 
the  Plymouth  Cordage  Company  in  a  two-story  shop,  114  ft. 
wide  and  430  ft.  long.  It  contains  2,400,000  bricks  made  with 


190     ENGINEERING  OF  SHOPS  AND  FACTORIES 

hand  machines,  the  proportion  of  cement  and  sand  being  1  to 
3.  Six  kinds  of  bricks  were  made,  and  the  rate  at  which  they 
were  produced  is  as  follows: 

Common  cement  bricks 14,000  per  day 

Face  bricks 9,000  per  day 

Radius  bricks .<? 8,000  per  day 

Corner  bricks 8,000  per  day 

Headers 9,000  per  day 

White  bricks 9,000  per  day 

Mortar  for  laying  cement  bricks  contains  cement  and  sand  in  the 
proportion  of  1  to  3,  with  a  half  sack  of  lime  added  for  each 
barrel  of  cement.  The  waste  was  only  one-half  of  1  per  cent, 
and  the  finished  cost  was  found  to  be  12  per  cent,  less  than  clay 
bricks. 

Concrete  Walls. — Concrete  walls  may  be  either  self  supporting 
and  solid  to  directly  sustain  imposed  loads,  or  they  may  be  used 
as  curtains  between  the  structural  members  of  steel  or  concrete. 
The  latter  method  is  now  generally  used  and  is  the  cheaper  and 
more  convenient,  as  the  structure  can  be  erected  first  and  the 
walls  filled  in  afterward.  Exterior  concrete  curtain  walls 
should  never  be  thinner  than  4  in.,  and  they  may  be  veneered 
with  brick,  as  on  the  Bullock  Electric  Company's  shops  at 
Cincinnati.  For  the  purpose  of  anchoring  the  brick,  strips  of 
metal  should  be  tacked  lightly  to  the  inside  of  the  wood  forms  and 
built  4  in.  into  the  concrete.  When  the  forms  are  removed,  these 
anchors  can  be  straightened  out  and  built  into  the  brick  joints, 
thus  firmly  uniting  the  two  materials.  When  the  walls  are  not 
veneered,  the  concrete  surface  may  be  treated  by  any  of  the 
methods  given  in  the  chapter  on  "  Concrete  Surface  Finish." 
The  original  building  for  the  United  Shoe  Machinery  shop  at 
Beverly,  Mass.  (Fig.  94)  was  made  with  solid  walls,  but  when 
making  additions  in  1907,  the  walls  were  cored.  Concrete  curtain 
walls  8  in.  thick,  when  cast  in  place  with  double  wooden  forms 
after  the  skeleton  is  finished,  cost  about  40  cents  per  square 
foot,  but  when  poured  at  the  same  time  as  the  columns,  the  cost 
is  increased  to  about  48  cents  per  square  foot.  Curtain  walls  or 
filling  slabs  4  in.  thick,  when  poured  as  described  above,  cost 
35  cents  per  square  foot.  It  appears,  therefore,  that  walls  of 
8-in.  concrete  and  12-in.  brick  cost  about  the  same  (Fig.  95). 

Monolithic  concrete  walls  have,  however,  been  recently  made 


WALLS,  PARTITIONS  AND  OPENINGS  191 


8-  V 'Vertical 'Bars. 
<4'BorrCcn/4'Pr/cr>. 


Wbod 

Finished  3™t     S'"~ 
Floor  Line         Drip 


Expansion  Joint  in  Floors 
at  Centers  of  Main  Buildings 


r0M*n4M*««  Composition  Roofing     ,2-|'Bcrrs 

~  *    — ^-  ^  Concrete ,   I  _      i.,,i,irr 


FIG.  94. — United  Shoe  Machinery  Co.  Shops,  Beverly,  Mass. 


192     ENGINEERING  OF  SHOPS  AND  FACTORIES 

with  removable  metal  forms  at  a  great  saving  in  expense,  the 
actual  cost  with  unskilled  labor  being  as  follows: 

Twelve-inch  monolithic  concrete  walls,1  made  as  above,  cost 


T-Bars,  12  C.toC. 
twisted  Bars,  Vertical  18'CtoC. 
Tile  Roof 

•refe  Fill 


4  T-Bars,  • 
Staggered  18'C.toC. 
/"Cement  \    . 

Concrete  Fill   \ 


. 
*4°T-Bars,Stagt]ered  18  "C.foC 


Part    Front-    Fleva-Hon  . 


Vertical   Section. 


FIG.  95.  —  Details  for  concrete  building. 

Material  .......................    11.5  cents  per  square  foot 

Mixing  and  placing  .............     3.0  cents  per  square  foot 

Movable  metal  forms  ............      1.5  cents  per  square  foot 

Total  ......................    16.0  cents  per  square  foot 

Six-inch  monolithic  concrete  walls  cost 

Material  .......................   5  .  75  cents  per  square  foot 

Mixing  and  placing  .............    1.5    cents  per  square  foot 

Movable  metal  forms  ............    1.5    cents  per  square  foot 


Total 8.75  cents  per  square  foot 

If  a  surface  coat  is  desired  it  can  be  added  at  an  additiona  Icost 
of  2J  cents  per  square  foot.     The  concrete  itself  in  the  6-in. 
1  Cement  Age,  February,  1912. 


WALLS,  PARTITIONS  AND  OPENINGS  193 

walls  cost  $5.40  per  cubic  yard  or  20  cents  per  cubic  foot.  The 
cost  of  the  removable  steel  forms  has  been  found  to  be  about 
one-half  cent  per  square  foot  for  each  face,  while  wood  forms 
would  cost  at  least  5  cents  for  each  face.  Unskilled  labor  can  be 
used  on  monolithic  work,  whereas  block  walls  must  usually  be 
laid  by  masons  at  a  higher  rate  of  wages.  These  costs  are  re- 
markably low  for  a  wall  that  is  substantial  and  that  can  be  made 
attractive  at  an  aditional  expense  of  2  or  3  cents  per  square  foot, 
as  elsewhere  described.  Walls  3  to  4  in.  thick,  of  previously 
moulded  concrete  slabs,  can  be  made  and  erected  at  a  cost  of 
8  to  10  cents  per  square  foot,  but  they  lack  the  rigidity  of  mono- 
lithic work.  (See  " Separately  Moulded  Members".) 

Wooden  Walls. — These  are  but  little  used  in  modern  shops  and 
should  be  covered  with  slate,  shingle,  or  metal  siding  either 
stamped  or  rolled.  Plank  with  splines  or  tongue  and  groove 
may  stand  vertically  and  be  fastened  to  horizontal  girths,  and 
square  edged  plank  may  have  the  vertical  joints  covered  with 
^-in.  battens.  If  the  planks  are  laid  diagonally,  they  form 
substantial  bracing  for  the  building,  though  the  diagonal  cutting 
causes  some  waste.  Planks  should  be  horizontal  when  the 
walls  are  covered  with  slate  or  metal.  A  weather  boarded  wall 
over  plank  not  including  the  framing;  will  cost  10  to  12  cents  per 
square  foot. 

The  comparative  cost  of  frame,  veneer  and  solid  brick  walls  is 
as  given  in  the  following  table : 

TABLE  XVIII 

FRAME 

Plastering .  .    $0 . 24  per  square  yard 

Lumber,  18  ft.  at  2  1/2  cents 45  per  square  yard 

Siding,  12  ft.  at  3  1/2  cents 42  per  square  yard 

Painting  per  yard,  two  coats 17  per  square  yard 

Paper  per  yard  put  on 03  per  yard  square 

Back  plaster 20  per  square  yard 

Total $1.51  per  square  yard 

BRICK  VENEER 

Plastering $0 . 24  per  square  yard 

Lumber,  18  ft.  at  1\  cents 45  per  square  yard 

Paper 03  per  square  yard 

Face  brick,  63  at  3  cents 1 .89  per  square  yard 


Total $2.61  per  square  yard 

13 


194     ENGINEERING  OF  SHOPS  AND  FACTORIES 

SOLID  BRICK 

Face  brick,  63  at  3  cents $1 . 89  per  square  yard 

Common  brick,  126  at  1  cent 1 .26  per  square  yard 

Furring 06  per  square  yard 

Plastering 24  per  square  yard 


Total ., $3 . 45  per  square  yard. 

•  *  * . .  v* 

Brick  veneer  will  therefore  cost  for  the  whole  building  25  per  cent, 
more  than  frame,  and  solid  brick  about  40  per  cent,  more  than  the 
frame  building. 


FIG.  96. — Tile  wall  for  four-story  building.     Thickness  4  to  12  in. 

Partitions. — Departments  which  generate  noise,  gas,  smoke, 
fumes,  or  dust  must  be  partitioned  off  from  other  parts  of  the 
shop,  and  these  departments  will  include  rooms  for  polishing, 
grinding,  rattling,  Japanning  and  painting.  These  partitions 
are  cheapest  and  most  conveniently  made  of  thin  terra  cotta 
blocks  or  hollow  tile  2  to  4  in.  thick  (Figs.  96-97)  for  they  can 
easily  be  removed  when  other  arrangement  is  needed.  When 
removal  and  rearrangement  is  improbable,  partitions  may  be 


WALLS,  PARTITIONS  AND  OPENINGS  195 


"Phoenix"  Wall,  with  piers,  smooth  or  ribbed  for  plastering 

FIG.  97. — Tile  wall  with  pier.     Blocks  either  smooth  or  ribbed  for  plastering. 


PLflST£R, 


PLHSTER  •/ 
PLASTER* 


SPflCE. 

U&^^assH^feaaag 


5*3  &?&3iii-Xi*3i 


CLAMf*) 


^^"^ 


FIG.  98. — Concrete  channel  block  partitions  and  wall  furring. 


196     ENGINEERING  OF  SHOPS  AND  FACTORIES 

of  reinforced  concrete  (Fig.  98)  or  expanded  metal  on  light  fram- 
ing. Mackite  blocks  2  in.  thick  have  frequently  been  used  and 
are  easily  erected,  as  they  are  12  in.  wide  and  4  feet  long.  As  the 
blocks  are  "soft,  they  should  be  coated  with  adamant  plaster. 
Some  makers  of  expanded  metal  also  manufacture  metal  studs 
with  outstanding  prongs  ready  for  cjinching  when  the  expanded 
metal  is  in  position.  These  studs  greatly  simplify  the  work  of 
partition  building.  Concrete  and  expanded  metal  walls  2  in. 
thick  cost  20  cents  per  square  foot. 

Windows. — One  of  the  chief  differences  between  old  manu- 
facturing buildings  and  new  ones  is  in  the  amount  of  light  ad- 
mitted, modern  ones  frequently  having  three  to  four  times  as 


FIG.  99. — A  modern  plant  for  Dodge  Brothers  Co.,  Detroit. 

much  as  their  predecessors.  In  fact,  the  exterior  walls  are  now 
composed  chiefly  of  glass,  many  having  window  areas  of  70  to  80 
per  cent,  of  their  exterior  surface  (Fig.  99) . 

When  walls  have  brick  on  the  outside,  the  size  of  window 
frames  should  be  made  to  suit  an  even  number  of  brick  courses  to 
avoid  cutting  the  brick.  Cypress  was  formerly  used  for  large 
sash  and  frames,  but  it  has  been  found  to  warp  easily,  and  pine 
is,  therefore,  preferred.  Nearly  all  of  the  latest  shops,  however, 
have  steel  frames  and  sash,  provided  with  opening  mechanism, 
to  operate  a  number  of  sash  at  once  (Fig.  100) .  Trunnions  should 
turn  in  brass  sockets  to  avoid  any  possibility  of  binding  from  rust. 


WALLS,  PARTITIONS  AND  OPENINGS 


197 


A  good  arrangement  for  side  wall  windows  is  to  have  three  tiers 
of  sash,  the  upper  one  being  pivoted  for  ventilation  and  the  two 
lower  ones  hung.  In  cold  climates  windows  should  be  double 
glazed  to  save  expense  in  heating. 

3  Z-Bar  f urnishSd  by  Steel  Contractor  «-  FlashinS  by  Roofer 


k~3 


Height  of  sash  (A)  less 

lVi"lap  equals  the  height 

of  opening  (B) 

Table  of  Openings  for 
Standard  Sash 

B 
2 

3'  10H 
4' 
S' 

A  —  Sash 
B —  Opening 
3  Continuous  Angle  by 
Steel  Contractor 


Pond  Operating  Device 


Vertical 

Section 

two  sash 

high 


Clip  and  Angle 

by  Steel  Contractor^ 
Flashing  by  Roofer 


Vertical 

Section  one 

sash  high 


FIG.  100.  —  Detail  of  Monitor  windows. 


Doors. — All  doors  in  multi-story  buildings  should  be  fire- 
proof, and  at  the  stairs  they  should  have  fusible  link  attach- 
ments, tin-clad  doors  being  preferable  to  sheet  metal  ones. 


198     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Storage  buildings  are  often-  provided  with  double  sets  of  doors, 
solid  ones  to  close  at  night,  and  inner  ones  for  use  during  the  day 
with  open  slats  which  will  allow  air  to  circulate. 

Car  shed  doors  10  ft.  by  16  ft.  are  economical  and  convenient 
when  made  of  wood  and  hung  on  cast-iron  eyelets  built  into  the 
wall.  They  may  have  glass  in  the  upper  panels,  and  the  cost 
should  not  exceed  about  $100.  Rolling  steel  shutters  for  the 
same  place  would  probably  cost  $160  to  $170. 

In  special  places  where  loading  cranes  must  extend  out 
through  the  side  walls  of  a  building  to  cover  an  adfoining  line  of 
railway,  a  rolling  steel  shutter  may  be  mounted  on  wheels  to  move 
out  from  the  building  in  advance  to  the  crane  and  return  again 
to  its  original  position  on  the  side  of  the  building,  when  the  crane  is 
indoors.  For  more  complete  details  of  windows  and  doors  for 
shops,  see  TyrrelFs  "Mill  Buildings"  pages  331-373. 


CHAPTER  XVII 
ROOFS    AND    ROOFING 

The  weight  and  permissible  roof  inclination  for  different  kinds 
of  roofing  are  given  in  the  following  table.  From  this  it  appears 
that  either  the  inclination  or  its  covering  can  be  selected  arbi- 
trarily, but  when  a  choice  of  one  of  these  has  been  made,  the  other 

TABLE  XIX.— ROOF  COVERING— WEIGHT  AND  LIMITS  OF  SLOPE 


Material 

Slope  (ir 
from  the  J 

L  degrees) 
horizontal 

Weight  in 
pounds  per 

From 

To 

square  foot 

Corrugated  iron  on  purlins 

5 

30 

5 

Zinc  on  boards  

0 

30 

5 

Zinc  on  purlins 

o 

30 

7* 

Lead  on  boarding  

Flats  and 

gutter  only 

10 

Lead  and  purlins 

Flats  and 

gutter  only 

12* 

Slates  on  boarding  

20 

45 

12i 

Slates  and  purlins 

20 

45 

15 

Tiles  on  battens  and  rafters  
Tiles  and  purlins       

30 
30 

70 
70 

17* 
20 

D 


FIG.  101. — Tile  roof  details. 


must  conform  to  it.  The  slope  must  be  great  enough  to  shed 
water  over  the  joints  or  seams  of  the  diffierent  coverings,  and  flat 
enough  in  some  cases  to  permit  the  covering  to  be  placed. 

199 


200     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Roofing  is  made  in  great  variety,  including  tile,  slate,  com- 
position, sheet  metal,  and  wood  shingles,  and  these  are  sup- 
ported directly  on  purlins  or  on  plank  or  a  filling  of  concrete 
between  them,  such  filling  making  excellent  roof  bracing. 
Boards  should  be  strong  enough  to  support  a  man's  weight,  and 
the  maximum  span  lengths  fo'r  different  thicknesses  are  as  given 
in  the  following  table: 

TABLE  XX.— ROOF  BOARDING— THICKNESS  AND  SPjAN 


Thickness  in  inches 

Maximum  span 

1 

2  ft.  8    in. 

t 

3  ft.    6  in. 

4  ft.     1  in. 

1 

4.ft.    8  in. 

n 

5  ft.    3  in. 

11 

5  ft.  10  in. 

If 

6ft.    5  in. 

I* 

7  ft.    0  in. 

Buildings  in  which  acid  fumes  are  generated,  as  in  brass 
foundries,  must  be  covered  with  an  indestructible  material  such 
as  slate.  Uralite  has  been  used  in  England,  its  cost  being  about 
the  same  as  No.  20  corrugated  iron. 

Flat  roofs  should  be  framed  like  floors,  excepting  that  they 
should  have  a  slope  of  at  least  1/2  in.  per  foot,  and  they  are  most 
conveniently  covered  with  tin,  tar  and  gravel,  or  some  kind  of 
composition. 

Tin  roofing  (M.  F.  Brand)  is  sold  in  boxes  containing  110 
sheets  and  costs  about  $7.25  per  box.  The  actual  cost  of  laying 
it  will  be  about  6  cents  per  square  foot  additional.  Previous  to 
laying  the  metal,  the  roofing  boards  should  be  overlaid  with  three 
layers  of  tar  paper  fastened  down  with  nails  and  tin  washers. 

The  quantities  of  material  required  to  lay  one  square  of  tar 
and  gravel  roofing,  are: 

Sheathing  paper 100  sq.  ft. 

Tarred  felt 80  to  90  Ib. 

Coal  tar  pitch 120  to  160  Ib. 

Gravel 400  Ib.,  or  slag  300  Ib. 


ROOFS  AND  ROOFING  201 

Felt  weighs  15  Ib.  per  100  sq.  ft.  with  an  addition  of  10  per  cent, 
for  laps.  When  burlap  and  felt  are  used  the  cost  will  be  about 
$4.50  per  square  (100  sq.  ft.),  or  slabs  can  be  covered  with  felt 
and  asphalt. 

Concrete  Roofs. — Concrete,  while  somewhat  heavier  than  wood, 
is  often  favored  because  it  is  fireproof,  and  when  covered  with 
roofing  material  to  shed  water,  cinder  concrete  can  be  used,  as 
on  the  buildings  at  the  Brooklyn  Navy  Yard,  where  the  3J-in. 
slabs  of  concrete  and  expanded  metal  are  covered  with  slate.  If 
a  concrete  roof  with  a  considerable  pitch  or  slope  is  to  be  covered 
with  tile,  wood  nailing  strips  parallel  with  the  eave  should  be 
cast  into  the  slabs. 

Concrete  Shingles. — Shingle  machines  are  sold  for  $100  to 
$200,  that  are  quite  similar  to  those  for  making  concrete  blocks. 
One  make  of  machine  produces  a  cement  shingle  8  in.  wide,  16  in. 
long,  and  J  in.  thick  at  the  butt,  each  shingle  being  reinforced 


FIG.   102. — Water  proof  concrete  tile. 

with  metal  which  projects  in  loops  at  each  side  for  nailing.  They 
are  composed  of  cement  and  sand  in  the  proportion  of  1  to 
1J  mixed  dry,  with  water  added  afterward.  At  the  end 
of  twenty-four  hours  they  are  removed  from  the  moulds  and 
stacked  in  the  yard  for  thirty  days,  being  sprinkled  occasionally 
for  a  few  days  after  making  them.  The  cost  of  labor  and 
materials  will  vary  in  different  sections,  and  hand  machines  will 
make  from  300  to  400  shingles  per  day. 

Concrete  Tile. — Waterproof  concrete  tiles  (Fig.  102)  supported 
directly  on  purlins,  have  come  rapidly  into  use  and  have  many 
advantages.  They  were  first  made  in  the  United  States  in  1902. 
Their  extreme  size  is  26  by  52  in.  and  J  in.  thick,  and  they  lay 


202     ENGINEERING  OF  SHOPS  AND  FACTORIES 

24  by  48  in.  to  the  weather,  weighing  in  position,  about  13  Ib.  per 
square  foot.  Purlins  must  be  4  ft.  apart  on  centers.  Tiles  are 
reinforced  with  number  18  expanded  metal.  With  this  roofing 
glass  skylights  are  unnecessary,  as  any  desired  proportion  of  glass 
tiles  can  be  substituted  for  the  regular  ones,  and  they  can  be 
arranged  as  desired,  either  in  clusters-or  in  small  scattered  areas. 


CHAPTER  XVIII 
NOTES  ON  SPECIAL   BUILDINGS 

The  Drafting  Office. — The  importance  of  the  drafting  office  can 
better  be  comprehended  when  it  is  considered  that  not  less  than 
$50,000,000  in  wages  is  paid  annually  to  draftsmen  in  the  United 
States,  and  other  countries  can  doubtless  show  similar  propor- 
tions. As  the  drafting  room  is  the  place  where  inventions  are 
made  and  developed,  and  details  of  construction  determined, 
every  facility  should  be  provided  that  will  assist  in  these  direc- 
tions. Engineers  and  designers  should  not  be  tied  down  to 
routine  work  or  to  exact  hours,  for  such  restrictions  are  a  hin- 
drance to  thought  and  study.  An  hour  or  two  over  a  drawing 
board  at  one  time  without  interruption  is  enough,  and  the  day's 
work  generally  should  not  exceed  eight  hours.  It  should  be 
remembered  that  in  this  office,  wealth  can  either  be  made  or  lost 
for  the  factory  owners,  and  the  greatest  latitude  should  be  given 
to  men  who  are  capable  of  creating  profits  and  saving  in  expense. 
Those  who  have  the  faculty  for  design  should  not  be  hampered, 
for  the  day  is  short  enough,  and  when  fatigued  with  trivial 
duties  even  an  inventive  mind  must  take  time  to  rest. 

The  drafting  office  (Fig.  103)  in  all  its  particulars  should, 
therefore,  be  made  to  assist  its  occupants  in  doing  their  best. 
Good  light,  air,  and  a  comfortable  degree  of  warmth  are  essentials, 
but  nothing  is  more  important  than  order.  Attention  cannot  be 
concentrated  on  a  subject  to  the  best  advantage  in  a.room  where 
papers  and  litter  of  every  kind  are  piled  about,  and  since  papers 
must  accumulate  rapidly  in  a  drafting  office,  there  should  be 
facility  for  filing  them  where  they  can  be  easily  reached.  Room 
interiors  and  furniture  should  preferably  be  finished  in  light 
tones,  for  dark  colors  absorb  light.  Upper  sash  may  have  ribbed 
glass  which  diffuses  daylight  better  than  plain,  but  the  lower 
glass  should  be  clear,  that  men  may  rest  their  eyes  by  occasional 
distant  views.  Each  window  should  have  two  shades,  one 
for  each  sash.  The  office  must  also  be  well  ventilated,  for 
cle'ar  thought  is  impossible  in  a  foul  atmosphere,  and  rooms 

203 


204     ENGINEERING  OF  SHOPS  AND  FACTORIES 

should,  therefore,  be  high  and  in  warm  weather  should  have  fans. 
They  should  be  large  enough  that  each  man  will  have  not  less  than 
100  sq.  ft.  of  floor  space,  and  there  should  be  enough  toilets  and 
wash  bowls  to  provide  one  for  every  twelve  to  fifteen  occupants. 
Office  equipment  should  be  selected  with  a  view  to  promoting 
order  and  convenience  both  as  to  quantity  and  kind  of  furnishing. 
Inclined  or  horizontal  drawing  boards  are  better  than  vertical 
ones,  because  standing  all  day  with  extended  arms  before  a  ver- 
tical board  is  too  fatiguing.  One  or  more  illuminated  drawing 


FIG.   103. — A  drafting  office. 

boards  are  convenient  for  tracing  blueprints.  The  board  is,  in 
fact,  a  piece  of  plate  glass  in  a  wooden  frame  with  facility  at  the 
edges  for  clamping  the  drawing  down.  It  has  electric  lights  be- 
neath the  glass  to  illuminate  the  blueprint  from  below.  A 
small  printing  press  is  a  saving  of  time  in  putting  on  titles  or  other 
wording  that  is  repeated  on  several  sheets.  It  can  also  be  used 
for  printing  time  cards,  office  forms,  blanks  and  similar  papers. 
Printers'  ink  which  dries  slowly  and  is  likely  to  smear  should  be 


NOTES  ON  SPECIAL  BUILDINGS  205 

sprinkled  over  with  powdered  chalk  or  soapstone.  Draftsmen 
should  also  have  the  use  of  a  writing  machine  for  tabulating  or 
copying,  and  carbon  negatives  may  be  made  on  thin  paper  that 
can  easily  be  blueprinted. 

A  hektograph  capable  of  making  from  sixty  to  eighty  dupli- 
cates is  useful  for  copying  simple  sketches.  The  block  is  com- 
posed of  white  lead  and  glue  poured  into  a  shallow  pan  and  al- 
lowed to  harden.  Drawings  for  use  on  the  hektograph  should  be 
made  on  cloth  with  special  ink,  and  as  the  ink  does  not  dry,  the 
ruler  should  be  raised  slightly  above  the  cloth  on  border  strips  to 
avoid  smearing  it.  These  inks  can  be  bought  in  several  colors. 
This  method  of  copying  is  very  useful  for  small  drawings,  and 
especially  for  blank  forms  such  as  bolt  and  rivet  lists,  for  when 
blanks  are  made,  three  or  four  copies  can  be  filled  out  at  one  time 
with  the  use  of  carbon  paper  in  a  typewriter. 

Other  simple  sketches  may  be  drawn  directly  on  paper  and 
several  carbon  copies  made  by  ruling  over  a  hard  surface,  such  as 
polished  wood  or  a  sheet  of  metal. 

A  large  camera  is  extremely  useful  in  connection  with  the 
drafting  room.  Photographic  views  of  buildings  or  machinery 
can  be  reproduced  in  pen  and  ink  sketches  by  tracing  over  the 
photograph,  and  from  these  sketches,  zinc  etchings  can  be  made 
at  a  cost  of  5  cents  per  square  inch.  The  camera  is  also  useful  for 
reproducing  drawings  and  reducing  them  to  a  small  size  which 
can  be  conveniently  handled,  especially  for  outdoor  use  or  erec- 
tion purposes.  When  reducing  large  drawings  by  photography,  it 
is  only  necessary  to  use  solid  lines,  and  large  open  printing  which 
can  be  read  easily  on  the  reduction.  Photographs  and  blue-prints 
can  be  mounted  on  cards  or  pasteboard  for  the  shop,  and  shellaced, 
and  then  if  they  become  soiled  they  can  easily  be  cleaned. 

The  cylindrical  arc  light  blueprinting  machine  is  the  best  and 
most  reliable  for  all  kinds  of  weather,  but  the  office  should  also 
have  one  or  more  sunlight  frames.  Whenever  alterations  are 
made  on  blueprints  that  have  already  gone  to  the  shop,  the  date 
of  such  alterations  should  be  noted  thereon.  Blueprints  may  be 
photographed  by  changing  them  to  brown  in  the  following  way. 
The  prints  should  first  be  immersed  in  a  dilute  solution  of  am- 
monia until  the  blue  disappears.  They  are  then  washed  in  water 
and  placed  in  a  weak  solution  of  tannic  acid  until  they  turn 
brown.  The  prints  should  again  be  washed  with  water  and 
dried,  when  they  can  easily  be  photographed. 


206      ENGINEERING  OF  SHOPS  AND  FACTORIES 

Machines  are  now  available  which  will  transform  drawing 
paper  into  a  translucent  sheet  like  tracing  paper  that  can  be 
blueprinted,  and  this  method  may  sometimes  be  used  to  advan- 
tage when  drawings  have  been  made  on  paper  instead  of  cloth. 

A  record  book  of  contracts  should  be  kept  by  the  chief  drafts- 
man or  office  manager,  and  this  should  consist  of  duplicate  pages 
alternately  white  and  yellow,  the  yellotv  being  used  for  a  carbon 
copy.  Then,  when  work  in  the  drafting  office  is  assigned,  the 
duplicate  copy  can  be  torn  out  and  handed  to  the  draftsman. 

Machine  Shops. — These  buildings  must  have  space  for  planers, 
lathes,  and  other  tools,  as  well  as  storage  room  for  completed 


—  Hi' Rods  run 
Horizontally  around  o 
ferfrcat  ~Rods  > 
every  Z'O'in  Height:  , 

— T 


FIG.  104. — Forge  shop.     United  Shoe  Machinery  Co.,  Beverly,  Mass. 

and  partially  completed  work,  and  space  for  assembling  machin- 
ery and  for  toilets,  lavatory  and  shop  office.  Some  form  of 
wooden  floor  as  described  in  Chapter  XIII,  is  the  best,  as  these 
are  comfortable  to  stand  on,  can  be  kept  clean,  and  when  sharp- 
edged  tools  drop,  they  are  not  injured.  The  absence  of  dust  in 
machine  shops  is  important,  and  especially  the  kind  that  fre- 
quently rises  from  a  concrete  floor,  for  it  settles  in  the  machinery 
bearings  and  is  likely  to  injure  them.  Other  requisites  common 
to  all  modern  shops,  such  as  light  and  ventilation,  are  likewise 
appropriate  here. 

Forge  Shops. — Blacksmith  shops  will  contain  steam-hammers. 


NOTES  ON  SPECIAL  BUILDINGS 


207 


bulldozers,  forges  and  anvils,  furnaces,  iron  and  fuel,  and  space 
for  a  wash  room  and  for  an  office.  They  should  have  provision 
for  heating  in  cold  weather  without  depending  on  the  forge  fires. 
One  chimney  (Fig.  104)  is  generally  enough  for  six  ordinary 
forges,  but  for  down  draft  only  one  chimney  is  needed  for  the 
whole  building.  Material  should  be  stored  in  a  separate  ware- 
house and  brought  into  the  shop  only  as  required.  The  clear 
height  underneath  the  trusses  should  not  be  less  than  about 
14  ft.,  and  side  walls  should  have  at  least  6  ft.  of  continuous  sash. 
Artificial  light  will  be  bright  enough  with  6-ampere  arc  lamps 
hung  40  ft.  apart.  The  best  floor  for  a  forge  shop  is  a  5-in.  layer 
of  cinders  over  a  base  of  sand  and  gravel.  The  cinders  should 
contain  just  enough  clay  to  cement  them  well  together,  and  the 
floor  should  be  rolled  and  sprinkled  every  day  for  a  month.  To 
prevent  mud  forming  from  the  cementing  clay,  the  surface 
should  be  covered  with  a  layer  of  sand. 

Foundries. — The    foundry    must    have    space    for    machine 
moulding,  bench  moulding  and  core  making,  as  well  as  for  sand 


•470'8'~ 


FIG.  105. — Rectangular  engine  house. 

mixing  and  storage,  coke  storage,  sand  blast  and  cleaning, 
charging  and  cupola  floors,  supply  room,  lavatories  and  office. 
There  is  a  decided  tendency  in  foundries  toward  the  use  of  square 
buildings.  Cupola  rooms  are  set  in  the  side  bays  away  from  the 
main  shop.  Transportation  on  the  ground  only  is  not  always 
economical,  and  there  should  generally  be  overhead  appliances 
as  well.  Cranes  and  trolleys  should  hang  from  a  heavy  system 
of  trusses,  leaving  the  floor  free  from  obstruction  of  columns. 

Round  Houses. — In  choosing  between  rectangular  (Fig.  105) 
and  circular  engine  houses,  the  first  form  requires  about  50  per 


208     ENGINEERING  OF  SHOPS  AND  FACTORIES 

cent,  less  floor  area  than  the  second,  and  has  straight  walls  and 
less  doors,  making  a  rectangular  building  altogether  cheaper 
than  a  round  one.  But  the  latter  type  has  other  advantages 
and  continues  in  favor. 

The  dimensions  of  a  round  house  will  depend  on  the  length 
of  engines  (Fig.  106) .  Turntables  moved  by  an  electric  tractor  or 
compressed  air  must  be  a  few  feet^onger  than  the  engine,  and 
enough  space  must  be  left  for  doors  to  open  between  the  table 
and  the  inner  engine  house  wall.  Doors  should  be  10  ft.  wide, 


FIG.   106. — Circular  engine  house. 

thus  leaving  some  clearance  at  each  side  of  the  engine  (Fig.  107). 
By  fixing  on  a  minimum  width  of  pilaster  between  the  doors, 
the  panel  length  at  the  inner  wall  will  be  determined.  Sliding, 
swing  and  rolling  doors  have  all  been  used,  but  as  those  which 
swing  on  hinges  at  the  side  are  in  danger  of  being  clogged  with 
snow  and  ice,  a  balanced  door  is  sometimes  preferred.  Steel 
rolling  doors  cost  more  than  either  of  the  others.  The  width  of 
the  building  should  be  10  to  15  ft.  greater  than  the  length  of  the 
engine,  allowing  space  for  workmen  to  pass  when  the  doors  are 
closed.  A  width  of  92  ft.  is  generally  enough  for  ordinary  large 
locomotives,  but  Mallet  engines,  some  of  which  have  a  length  of 
120ft.,  will  require  special  housing.  Figure  108  shows  a  turn- 
table in  use  on  the  A.  T.  &  S.  F.  Ry,  for  turning  Mallet  engines. 


NOTES  ON  SPECIAL  BUILDINGS 


209 


Walls  should  be  of  brick  or  concrete  blocks,  because  monolithic 
concrete  is  too  inconvenient  to  repair  when  damaged,  though  it 
is  suitable  for  the  foundations.  As  runaway  engines  occasionally 
go  through  the  outer  wall,  it  is  better  to  place  an  arch  or  lintel 
at  the  end  of  each  track,  which  would  prevent  the  roof  from 
falling  if  the  walls  should  be  broken  down.  The  building  should 
be  divided  by  occasional  fire  walls,  six  to  eight  stalls  apart,  and 
these  should  extend  above  the  roof. 


FIG.  107. — Inside  and  outside  elevations  of  roundhouse. 

Vitrified  brick  grouted  in  tar  or  pitch  makes  the  best  floor. 
Wood  wears  out  too  quickly,  and  concrete  with  granolithic  top 
is  easily  cracked  or  broken  under  the  weight  of  trucks  and  wheels. 
Pits  under  the  tracks  should  be  50  to  60  ft.  long,  4J  ft.  wide 
and  2  to  3J  ft.  deep,  and  they  should  be  convex  at  the  bottom 
allowing  water  to  drain  to  either  side  (Fig.  109). 

14 


210     ENGINEERING  OF  SHOPS  AND  FACTORIES 


NOTES  ON  SPECIAL  BUILDINGS 


211 


Roofs  should  slope  away  from  the  turntable  and  when  steel 
trusses  are  used,  a  ceiling  should  be  placed  below  them,  because 
steel  is  rapidly  corroded  by  gases  from  the  engines.  Wood  or 
concrete  framing  is,  therefore,  preferable.  Concrete  roofs  in 
very  cold  climates  should  be  double,  or  have  some  other  provision 
for  preventing  condensation.  When  slate  covering  is  used,  the 
outer  purlins  may  be  slightly  convex,  and  the  inner  ones  concave, 
to  avoid  hips  and  valleys  at  the  trusses,  but  for  tar  and  gravel 
roofing  curved  purlins  are  unnecessary. 


Section  A-A.     (Fig. 5. 1 
/3x8'Hemlocfr 


H 

Transverse     Section. 


K- — M'—*\ 
Lonqitudinal     Section     at    \ ». 

FIG.  109. — Pit  details  for  locomotive  shops. 


Windows  should  cover  most  of  the  outer  wall  and  they  should 
be  balanced  on  trunnions  and  operated  in  clusters  by  a  shaft  and 
wheel.  Those  over  the  doors  should  also  be  pivoted  for  the 
sake  of  ventilation.  Skylights  or  swing  sash  on  monitor  sides 
may  be  used,  and  all  interior  surfaces  above  a  dark  colored  dado 
5  ft.  high,  should  be  whitewashed  or  painted  a  light  color. 

Smoke  jacks  are  sometimes  made  of  asbestos  lumber  and  they 
should  fit  down  tight  over  the  stacks,  and  have  dampers  to  stop 
the*  draft  when  not  in  use.  Monitor  windows  or  individual 
ventilators  will  supply  more  ventilation  when  it  is  needed. 
Round  houses  in  cold  climates  must  be  heated,  preferably  by  a 


212     ENGINEERING  OF  SHOPS  AND  FACTORIES 

hot  blast,  though  steam  pipes  are  sometimes  used.  Circular 
round  houses  complete  usually  cost  from  $1300  to  $1600  per 
stall. 

Car  Shops. — The  size  and  weight  of  parts  made  and  handled  in 
car  shops,  necessitate  a  one-story  building  with  floor  on  the  solid 
gound.  The  location  for  these  shops.,  is  important,  as  they 
usually  need  a  large  area  of  land,  not  only  for  spreading  out  their 
one-story  buildings,  but  for  storing  cars  and  bulky  material.  A 
tract  just  outside  of  some  large  city  is  usually  the  best,  where  land 
values  and  taxes  are  low  and  abundance  of  labor  near  at  hand. 
Plenty  of  extra  land  should  be  acquired  at  first,  so  there  will  be 
room  for  expansion.  In  flat  or  low  regions  like  the  prairie  states, 
it  is  often  best  to  raise  the  grade  from  2  to  4  ft.  above  the 
surrounding  country,  and  where  natural  drainage  is  not  available, 
sewers  may  empty  into  an  artificial  sump,  from  which  the  drain- 
age can  be  pumped  and  discharged  into  the  nearest  watercourse. 
An  excellent  method  of  arranging  the  buildings  is  to  place  them 
right  and  left  of  a  central  elevated  craneway,  crossing  trans- 
versely all  the  tracks  which  enter  the  successive  buildings  and  the 
sidings  parallel  to  them.  By  means  of  this  traveling  crane, 
material  from  any  of  the  buildings  may  be  loaded  on  to  cars  or 
lifted  from  them  and  conveyed  to  any  other  track  desired. 
When  city  water  is  not  obtainable,  an  underground  reservoir  must 
be  made  and  pressure  can  be  secured  from  an  elevated  tank 
100  ft.  in  height  or  more.  The  new  car  shops  at  Winnipeg,  Man. 
(Fig.  110),  which  are  among  the  finest  over  built,  are  laid  out  as 
described  above,  the  reservoir  being  60  ft.  wide,  270  ft.  long  and 
25  ft.  deep,  capable  of  holding  2,000,000  gallons,  and  the  elevated 
tank  125  ft.  high  will  hold  100,000  gallons. 

Car  Houses. — Buildings  for  the  storage  of  cars  (Fig.  Ill) 
contain  and  cover  goods  of  great  value,  and  as  paint,  oil  and 
varnish  are  used  about  them,  precaution  should  be  taken  to  pre- 
vent fire.  Walls  which  face  dangerous  exposures  should  be 
without  windows,  and  the  whole  building  should  be  divided 
by  fire  walls  extending  3  ft.  above  the  roof  into  ground  areas 
of  5000  to  20,000  sq.  ft.  Openings  in  the  walls  should  have 
fire  doors.  Framing  of  wood  mill  construction  has  been  found  to 
be  a  better  fire  risk  than  exposed  steel,  for  the  latter  collapses 
quickly  under  heat.  Cornices  should  be  of  brick  or  metal  rather 
than  of  wood,  and  windows  should  have  wire  glass.  Partitions 
should  be  fireproof  and  boiler  rooms  should  be  separated  from 


NOTES  ON  SPECIAL  BUILDINGS 


213 


214     ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  car  shed,  the  whole  plant  being  protected  against  fire  by  a 
liberal  use  of  fire  pails,  automatic  sprinklers,  stand  pipes,  and 
chemical  extinguishers. 

Cotton  Mills. — Columns  in  cotton  mills  should  be  spaced  23  ft. 
apart  on  centers  transversely  of  the  building,  and  the  inside 
width  will,  therefore,  be  46  ft.  .for  one  row  of  columns,  69  ft.  for 
two  rows,  and  92  ft.  for  three  rows,  I^or  greater  convenience, 
some  architects  use  outside  widths  of  50,  75,  and  100  ft.  re- 
spectively, and  corresponding  clear-story  heights  of  12,  13,  and 
14ft. 


FIG.  111. — A  car  house. 

Power  Houses. — Some  structural  features  of  power  house 
design  may  be  illustrated,  by  describing  briefly  two  plants 
recently  designed  by  the  writer,  in  connection  with  an  electrical 
engineer  in  each  case. 

The  first  of  these  (Fig.  112)  was  for  in  interurban  electric  rail- 
way company  in  Ohio.  It  consists  of  an  engine  room  52  by  146 
ft.  and  a  boiler  room  62  by  146  ft.,  containing  the  boilers  and  a 
suspended  coal  bunker  12  by  75  ft.  on  the  outer  side  of  the 
building,  adjoining  the  railway  company's  property.  The 
engines  and  heavy  electrical  machinery  stand  on  concrete  founda- 
tions, the  space  around  the  foundations  beneath  the  machinery 
floor  being  left  open  and  used  for  basement  or  cellar  storage. 
The  remainder  of  the  engine  room  floor,  not  occupied  by  the 
engine  foundations,  is  covered  with  a  reinforced  concrete  slab 
on  steel  beams.  The  steel  framing  of  this  floor  weighed  22  tons 
and  cost  $1100  in  place,  and  the  reinforced  concrete  slab  cost 
$3400  or  56  cents  per  square  foot. 

The  height  under  the  trusses  in  both  boiler  and  engine  room 


0A*  SPECIAL  BUILDINGS 


215 


1 
1 


4  Ls,  3^"x  2J& 
/  Plate  12"x  *" 

T      if 

1                              [1  co 

n 

I      I 


I] 


5-   S 


\    / 


y 


/  \ 


\  / 


fc-Wi 


co    In' 


\   / 


y 


\/  \ 


\  / 


y 


\      / 


\/  \/  \ 


\  / 


y 


\  / 


y 


\  / 


y 


I 

I 

I 


t 

-[ 

J 


6"! 


61 


6"! 


6  I 


G  I 


FIG.  112. — A  power  plant. 


216     ENGINEERING  OF  SHOPS  AND  FACTORIES 

is  24  ft.  Slate  covering  is  laid  on  2-in.  plank  carried  on  steel 
trusses  of  the  Fink  type  with  stiff  top  chords,  placed  16  ft. 
apart.  Jack  purlins  of  10-in.  channels  are  framed  between  the 
trusses  to  carry  7-in.  channel  jack  rafters,  5  ft.  4  in.  apart.  On 
the  top  of  each  truss  and  jack  rafter  is  a  3  by  5  in.  wood  nailing 
piece  to  which  the  plank  is  spiked,  the  joints  being  parallel  with 
the  eave  as  required  for  slate  coverhig.  Both  the  boiler  and 
engine  room  have  double  pitched  roofs,  forming  a  continuous 
gutter  over  the  center  partition  wall  between  the  two  rooms. 
At  the  ends  the  roofs  are  hipped,  and  two  panels  ovef each  room 
have  stiff-angle  bracing  in  the  plane  of  the  bottom  chord  to  keep 
the  trusses  properly  in  line.  These  two  braced  panels  are  united 
with  a  line  of  angles  in  the  center  of  each  span,  and  in  the  plane 
of  the  rafters  also,  the  same  two  panels  have  double  rod  bracing. 
The  trusses  stand  on  plate  and  angle  columns  in  the  walls  and  are 
rigidly  knee  braced  to  them.  In  the  engine  room  is  a  10-ton 
hand  traveling  crane  running  on  15-in.  beam  girders,  which  are 
carried  on  column  brackets.  The  presence  of  this  crane  enables 
the  various  parts  of  the  engines  and  machinery  to  be  set  or 
replaced  without  injuring  the  trusses.  Over  the  boilers  is  a 
continuous  ventilator,  48  ft.  in  length,  the  sides  of  which  are 
covered  with  fixed  louvres,  and  the  roof  with  slate  similar  to 
that  on  the  rest  of  the  building.  At  the  rear  of  the  boilers  is  an 
elevated  platorm  64  ft.  in  length,  framed  with  6- and  8-in.  beams, 
and  supported  on  steel  columns. 

The  brick  walls  serve  merely  as  curtains,  because  the  roof  and 
crane  loads  are  carried  directly  on  the  columns.  The  largest 
single  item  of  expense  in  the  steel  work  is  the  coal  bunker,  which 
has  a  capacity  of  200  tons.  Coal  is  hauled  up  an  incline  in  hopper 
bottom  cars  and  the  coal  is  emptied  from  them  into  the  bunkers, 
the  frame  of  which  is  strong  enough  to  safely  carry  the  weight  of  a 
car  holding  50  tons  of  coal  and  weighing  15  tons  when  empty. 
The  tracks  and  bunker  are  enclosed  and  covered  with  a  corru- 
gated iron  shed  as  protection  from  the  weather  and  the  snow. 
The  toe  or  lower  end  of  the  bunker  hangs  over  the  front  end  or 
doors  of  the  fire  box  and  boilers,  and  six  lines  of  chutes  convey 
the  coal  down  to  automatic  stokers.  The  discharge  of  coal 
through  these  chutes  is  regulated  by  means  of  swinging  gates 
operated  by  hand.  The  space  below  the  suspended  bunker  is 
used  by  the  workmen  in  the  boiler  room.  The  bunker  is  lined 
throughout  with  J-in.  steel  plates,  and  the  bottom  is  supported 


NOTES  ON  SPECIAL  BUILDINGS 


217 


on  9-in.  beams,  the  whole  being  suspended  from  two  lines  of  plate 
girder  one  on  each  side,  which  stand  on  steel  columns.  The 
space  between  the  track  stringers  is  left  open  for  admitting  coal 
from  the  hopper  cars,  and  the  stringers  are,  therefore,  braced 
over  to  the  plate  girders  at  the  sides.  The  quantities  of  steel 
in  the  various  parts,  and  the  cost  thereof,  are  given  in  the  fol- 
lowing schedule: 


Coal  bunker  for  50-ton  < 

Bunker  shed 

Engine-room  floor 

Steel  roof  frame 

Traveling  crane,  10  tons 


74  tons  of  steel,  cost  $5200 
18  tons  of  steel,  cost  2100 
22  tons  of  steel,  cost  1100 
65  tons  of  steel,  cost  4500 
. .1100 


10"t 


10"c 


10rc 


Stack 


L51L 


\ 


Itfc 


15  Ib 


15  Ib 


50-4— 


50-4—- 


FIG.  113. — Power  plant  at  Huntington,  W.  Va. 

The  other  power  house  (Fig.  113)  was  f  or  an  interurban  railway 
in  West  Virginia.  The  building  is  142  ft.  long  by  94  ft.  wide,  and 
is  divided  by  a  brick  wall  through  the  middle,  making  two  rooms 
of  equal  size.  The  engine  room  has  a  15-ton  hand  traveling 
crane  for  lifting  machinery  parts,  and  the  rails  on  which  the  crane 
runs  are  fastened  to  the  top  flange  of  the  crane  beams  with  hook 


218     ENGINEERING  OF  SHOPS  AND  FACTORIES 

bolts.  This  allows  adjustment  of  the  rails  to  suit  the  distance  be- 
tween the  crane  wheels.  The  roof  surface  of  both  rooms  is  covered 
with  28-in.  slate  on  steel  angle  purlins,  2  by  1J  by  T\  in.,  spaced 
13  in.  apart.  The  boiler  room  has  continuous  galvanized  iron 
louvres  on  the  monitor  and  the  engine  room,  four  circular  48- 
in.  galvanized  iron  ventilators.  Between  the  engine  beds  in  the 
dynamo  room  is  a  system  of  steel  beams  carrying  corrugated 
iron  arches  and  concrete  floor.  The  steel  work  in  the  floors  costs 
$1400,  and  the  weight  of  steel  in  the  roof  and  crane  system  is  75 
tons,  and  its  cost  $6200,  equivalent  to  about  45  cents  per  square 
foot  of  floor  covered. 


CHAPTER  XIX 
STORAGE  POCKETS,  AND  HOISTING  TOWERS 

In  recent  years,  the  handling  of  coal  in  large  quantities  has 
led  to  the  construction  of  several  new  forms  of  storage  pockets, 
some  of  which  are  herewith  illustrated.  While  these  pockets 
were  formerly  built  of  heavy  timber  that  would  decay  or  wear  out 
in  a  few  years,  they  are  now  framed  largely  of  steel,  and  in  many 
cases  are  also  lined  with  steel  plates. 


&>'P.6SJ/1 'ffip.tS'. 


j M-  365000 


$ 


FIG.  114.— A  200-ton  pocket. 

The  type  is  illustrated  by  a  plant  near  Boston,  which  contains 
four  pockets  having  a  capacity  of  2000  tons  each,  and  one 
pocket  with  a  capacity  of  6000  tons.1  Many  others  might  be 
mentioned,  such  as  those  at  Worcester,  Mass.,  and  a  large  one 
designed  by  the  writer  at  Montreal.  The  2000-ton  pocket 
(Fig.  114)  mentioned  above  was  35  ft.  wide,  80  ft.  long  and  72  ft. 
high  to  the  eave,  and  coal  was  conveyed  to  it  by  cable  cars 
running  on  steel  trestle  work,  the  cars  entering  the  pocket  through 

1  H.   G.  Tyrrell,  in  Railroad  Gazette,  Oct.  4,  1901. 

219 


220     ENGINEERING  OF  SHOPS  AND  FACTORIES 

openings  in  the  roof.  The  four  pockets  were  conveniently 
located  to  supply  coal  to  the  adjoining  ovens.  They  were  lined 
with  plank  and  covered  with  a  galvanized  iron  roof,  and  the 
total  weight  of  steel  in  one  pocket  was  510,000  lb.,  which  is 
equivalent  to  255  lb.  of  steel  for  every  ton  of  coal  stored.  The 
6000-ton  pocket  on  the  -dock  received  coal  directly  from  the 
vessels.  On  the  top  of  the  pocket  :above  the -roof  were  four  steel 
hoisting  towers  mounted  on  wheels,  and  the  position  of  the  towers 
could  be  suited  to  the  hatchways  in  the  ships.  This  pocket  was 
28J  ft.  wide,  and  432  ft.  long,  and  stood  on  a  framework  of 
beams  and  columns,  leaving  a  clear  headway  of  14  ft.  beneath 
for  the  passage  of  cars.  It  was  lined  inside  with  plank  which  is 
held  in  position  by  12-in.  I  beam  studs,  4  ft.  apart.  The 
sloping  hopper  sides  were  of  plank  on  timber  blocking.  Roof 
trusses  with  a  3-in.  pitch,  placed  12  ft.  apart,  carried  channel 
iron  purlins  and  corrugated  iron  covering.  The  hopper  gates 
were  extremely  simple  but  effective.  The  total  quantities  of 
material  in  the  6000-ton  pocket  were  as  follows: 

Steel  frame 942,000  lb. 

One  hundred  hoppers 39,000  lb. 

One  hundred  hopper  gates 17,000  lb. 

Corrugated  iron 14,500  sq.  ft. 

Spruce  lumber 17,300  ft.  B.  M. 

The  total  weight  of  steel  corresponds  to  166  lb.  for  every  ton  of 
coal  stored,  which  is  equal  to  3 J  lb.  of  steel  for  every  cubic  foot 
of  contents.  The  roof  had  small  hoppers  about  12  ft.  apart 
through  which  coal  was  received  from  the  hoisting  towers,  and 
the  pocket  in  turn  discharged  its  contents  into  cars  on  the  three 
tracks  underneath.  These  tracks  were  connected  with  inclined 
trestle  work  on  which  the  coal  was  conveyed  to  the  four  smaller 
oven  pockets. 

The  4000-ton  pocket  at  Montreal  is  28  ft.  8  in.  wide,  16J  ft. 
high  and  400  ft.  long.  Like  the  one  just  described,  it  stands  on  a 
frame  work  of  beams  and  columns,  leaving  a  clear  headway  of 
14  ft.  underneath  for  the  passage  of  cars.  In  designing  it,  the 
following  units  were  used : 

Weight  of  coal 50  lb.  per  cubic  foot 

Wind  pressure 30  lb.  per  square  foot 

Total  roof  load 40  lb.  per  square  foot 

Steel  in  tension 15,000  lb.  per  square  inch 

Steel  in  compression 12,000  lb.  per  square  inch 

Fiber  stress  in  beams 16,000  lb.  per  square  inch 


STORAGE  POCKETS  AND  HOISTING  TOWERS  221 

This  pocket  was  divided  into  thirty-three  panels  of  12  ft.  1J 
in.  and  was  lined  throughout  with  oak  plank.  The  total  weight 
of  steel,  including  the  pocket  itself  and  the  platform  of  beams  and 
columns  on  which  it  stands,  was  666,000  Ib.  This  is  equivalent 
to  166  Ib.  of  steel  for  every  ton  of  coal  stored.  Another  design 
for  the  same  pocket,  with  J-in.  steel  plate  lining  instead  of 
plank,  contained  983,000  Ib.  of  steel,  equal  to  245  Ib.  for  every 
ton  of  coal.  These  figures  do  not  include  in  either  case,  the  rails 
on  which  the  hoisting  towers  travel,  amounting  to  about  16,000 
Ib. 

The  above  weights  of  steel  correspond  to  3  to  4  Ib.  per  cubic 
foot  of  contents.  The  weight  of  steel  in  storage  pockets  varies 
almost  directly  according  to  the  number  of  tons  stored  and  for 
plank-lined  pockets,  is  from  160  to  170  Ib.  per  ton  of  contents, 
increasing  to  240-250  Ib.  per  ton  of  contents  where  the  pockets 
have  steel  lining.  If  they  are  designed  for  the  storage  of  some 
heavier  material  such  as  ore,  the  above  figures  will  still  apply. 
A  large  bin  designed  by  the  writer  for  export  to  South  Africa,  for 
the  storage  of  gold  ore  weighing  100  Ib.  per  cubic  foot,  contains 
7  Ib.  of  steel  per  cubic  foot  of  bin,  or  170  Ib.  of  steel  for  every  ton 
of  ore,  the  ratio  remaining  the  same  as  before.  These  figures 
give  a  ready  and  convenient  means  of  estimating  approximately, 
the  quantity  of  material  in  these  structures. 

The  coal  pocket  shown  in  Fig.  115  is  somewhat  similar  to  those 
previously  described,  but  in  this  case,  the  coal  is  brought  to  the 
site  by  rail  instead  of  water.  At  one  end  is  a  sloping  trestle,  upon 
which  cars  are  drawn  to  the  track  above  the  bin,  where  they  are 
emptied  through  sliding  hoppers  into  the  pocket.  The  loaded 
cars  are  delivered  on  an  adjoining  siding  and  are  taken  up  the 
inclined  trestle  by  means  of  a  cable  pusher,  which  is  operated 
from  an  engine  plant.  The  pocket  is  lined  with  3-in.  yellow  pine 
and  has  a  plank  roof  on  steel  stringers.  The  side  studs  are  4  ft. 
apart  and  the  main  panels  are  16  ft.  each. 

Suspension  bunkers  (Fig.  116)'  are  probably  the  most  economi- 
cal form  in  metal,  for  much  heavy  beam  framing  is  avoided,  and 
the  metal  plates  which  served  merely  as  a  lining,  in  the  form 
described  above,  now  support  the  load  by  tension.  The  type  is 
desirable  chiefly  when  metal  plates  are  required  inside.  For 
timber  lining,  the  old  style  with  plank  supported  on  a  system  of 
inclined  beams,  may  be  found  cheaper.  Patents  on  suspension 
bunkers  have  been  granted,  but  these  do  not  include  all  forms  of 


222     ENGINEERING  OF  SHOPS  AND  FACTORIES 


construction,  for  similar  pockets  are  made 
by  others  without  patented  features.  Metal 
has  the  advantage  of  occupying  somewhat 
smaller  space  than  timber  or  concrete  fram- 
ing. Pockets  of  some  kind  are  now  almost 
indispensable  for  power  houses  or  wherever 
a  large  quantity  of  coal  is  stored. 


Concrete  coal  pockets  of  3000  ton 
capacity  or  more,  cost  from  $5.50  to  $7.50 
per  ton  of  capacity,  and  concrete  stand 
pipes,  not  including  the  foundations,  cost 
from  2J  to  3  cents  per  gallon  of  contents. 
Combination  coal  pockets  with  supports 


STORAGE  POCKETS  AND  HOISTING  TOWERS  223 


r^- Double  Drum  HoistlngEnqim 


Ateon  Z-ow  7/bte      . 


FIG.  116. — Boiler  house,  showing  coal  handling  equipment.     Hecker  Flour 

Mills,  New  York. 


FIG.  117. — A  concrete  coal  pocket. 


224     ENGINEERING  OF  SHOPS  AND  FACTORIES 


'#%%fc%z%%t%£$%%!>z^^  ' 

Longitudinal  Section. 


rT 

"1"" 

"T 

Lt;ij 

¥tJ 

ut" 

II 

\ 

\ 

1 

D 

il    ii 

.J 

_     _E 

-.i 

-       -    JS 

i-  —  4. 

-    -    i 

i  ^n 

i  1 

<    IS'O"  • 

...-**•» 

i 

i 

.   _     _ 

___. 

'  **'-» 

-^ 

<•••  -is'o"-^ 

__jj 

r—  j 

1 
I 

fil 

L.__|J 

%  f 

s 

—  7 

i 

1        | 

Tl 

-^-'4 
|] 

| 

j 

1 

| 

ID         D 

a    «i  c 

\ 

l 

—  i 

L—4-_ 

i 

S 

s 

S 

$            D 

D       J^  C 

s 

! 

r  —  -  -| 

-*  —  1 

t;    i 

-5 

5 

i  —  .  — 

-p 

i  —  ^^ 

i  1  < 

fWt,,-- 

D  :<|jj  a 

LDH  ^  C 

i 

j 

\ 

1 

11 

i 

i] 

J 

| 

P  I  a  o  . 

FIG.  118. 


-2.C-C 


FIG.  119. — Ash  pocket  at  Philadelphia.     Philadelphia  Rapid  Transit  Co. 


STORAGE  POCKETS  AND  HOISTING  TOWERS  225 


15 


226     ENGINEERING  OF  SHOPS  AND  FACTORIES 

and  floor  of  concrete  and  walls  of  timber,  cost  about  $5  per  ton 
of  capacity.  Some  details  of  concrete  coal  pockets  are  shown  in 
Figs.  117  to  120. 

Hoisting  Towers.1 — Coal  hoisting  towers  on  the  wharfs  at  sea- 
board cities  were  formerly  constructed  of  wood,  as  were  also  the 
pockets  to  which  they  deliver  coal,  but  with  the  introduction  of 
steel,  many  were  afterward  built  ofmetal,  which,  though  more 
expensive  than  the  old  style,  make  a  safer  and  more  satisfactory 
hoisting  tower  (Fig.  121).  They  are  usually  mounted  on  wheels 
to  travel  on  the  top  of  a  storage  pocket,  all  of  those  ^described  here 
being  of  that  type.  Other  kinds  are  also  used,  where  the  tower 


FIG.  121. — Coal  handling  plant  at  Dollar  Bay, 

is  combined  with  a  lower  house  containing  the  weighing  and 
crushing  hopper,  the  whole  being  mounted  on  wheels  traveling 
on  the  ground.  A  design  of  this  kind  was  made  by  the  writer  for 
The  Boston  Elevated  Railroad  Company,  at  the  Lincoln  Wharf 
plant. 

The  type  of  tower  traveling  above  a  storage  pocket,  is  illus- 
trated by  one  for  the  Metropolitan  Street  Railway  Company  of 
New  York,  the  frame  being  55  ft.  high  and  24  ft.  square  at  the 
base,  with  a  single  boom  31  ft.  in  length  overhanging  the  water 
and  boats.  The  tower  has  four  legs  strongly  braced  together,  and 
the  lower  part  contains  an  engine  room  from  which  the  hoisting 
is  controlled.  The  engine  house  is  roofed  over  and  enclosed  on 
the  sides  with  corrugated  iron,  having  windows  enough  to  admit 

1  H.  G.  Tyrrell,  in  Engineering  News,  May  30,  1901. 


STORAGE  POCKETS  AND  HOISTING  TOWERS  227 


228     ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  light.  The  crushers  are  supported  on  framing  about  8  ft. 
below  the  engine  room  floor.  The  hopper  is  of  ^Q-'m.  plate 
with  a  frame  of  angle  and  channel  iron.  The  tower  was  designed 
to  carry  a  live  load  of  three  tons  at  the  end  of  the  boom  with  an 
allowance  of  100  per  cent,  for  impact.  It  contains  18  tons  of 
steel  and  cost,  including  floor,  roof  jind  sides,  $2250. 

Another  tower,  somewhat  similar  to  the  last,  designed  by  the 
writer  for  the  Dominion  Coal  Company  at  Montreal,  has  a  height 
of  63  ft.  and  a  boom  51  ft.  long,  with  a  base  29  ft.  long  and  25  ft. 
wide.  The  boom  is  swiveled  at  the  rear  end  and  was  propor- 
tioned for  a  live  load  of  3J  tons,  with  provision  of  100  per 
cent,  for  impact.  The  floor  is  very  heavy,  being  made  of  12-  and 
18-in.  steel  beams.  It  has  a  ladder  on  one  side,  enabling  the 
operator  to  inspect  and  oil  the  bearings  at  the  tower  top.  The 
total  assumed  load  at  the  end  of  the  boom  is  18,000  Ib.  The 
tower  is  mounted  on  seven  wheels  and  has  a  safety  clamp  at  the 
rear  to  prevent  tipping.  It  contains  27  tons  of  steel  besides  the 
trolley  rope  and  operating  machinery.  The  hopper  is  lined  with 
plank  and  the  house  enclosed  with  sheathing.  (Fig.  122.) 


CHAPTER  XX 


FACTORY  HEATING 

Heating  may  be  done  by  the  use  of  direct  or  exhaust  steam 
passing  through  coils  of  pipe,  or  by  warm  air  in  large  quantities 
forced  by  fans  through  ducts  to  different  parts  of  the  shop.  As 
the  latter  type  of  heating  is  the  one  best  adapted  to  shops  and 
factories  it  is  described  at  greatest  length  in  the  following  pages. 

In  the  heating  and  ventilating  of  industrial  buildings,  economy 
is  of  prime  importance,  and  it  is  from  this  standpoint  that  the 
acceptance  or  rejection  of  the  fan  system  must  be  decided,  though 
sanitation  even  from  a  mercenary  consideration  must  not  be 
disregarded,  for  upon  the  comfort  and  well  being  of  the  workmen 
must  their  efficiency  and  contentment  depend. 

Apparatus  for  Fan  System. — A  heating  system  is  composed  of 
three  essential  elements — the  heater,  the  fan  and  the  distribut- 


ffil  (ill*          h 


FIG.  123. — Fan  system  in  automobile  plant  of  George  M.  Pierce,  Buffalo. 

ing  ducts.  The  heater  consists  of  rows  of  vertical  1-in.  wrought- 
iron  pipes,  screwed  into  a  manifold  cast-iron  base  which  is  divided 
into  separate  units  or  sections.  The  coils  are  tightly  enclosed  on 

229 


230     ENGINEERING  OF  SHOPS  AND  FACTORIES 

the  top  and  sides  by  sheet  steel  casing.  The  air  is  drawn  or 
forced  through  between  the  pipes  by  means  of  a  centrifugal  fan 
which  connects  with  the  heater  casing.  The  fan  should  be  amply 
large  and  should  be  driven  at  sufficient  speed  to  produce  an  air 
velocity  of  about  1200  ft.  per  minute  through  the  clear  area  of 
the  coils.  This  velocity  is  an  important  condition  since  the 
effectiveness  of  the  coils  is  largely  dependent  upon  it.  The 
increased  efficiency  of  the  heating  surface  from  this  cause  is  so 
great  that  only  from  one-third  to  one-fifth  as  much  surface  is 
required  with  the  fan  system  as  with  direct  radiation.  Further, 
as  will  be  shown  later,  the  heat  is  so  applied  and  distributed  that 
it  is  far  more  thoroughly  utilized  than  in  ordinary  radiation. 

Heat  Losses. — Heat  losses  occur  in  a  building  from  two  causes. 
First,  by  the  direct  transmission  of  heat  through  the  walls  and 
exterior  surfaces  of  the  building,  and  second,  by  the  infiltration 
of  cold  air  from  without.  In  designing  a  heating  plant,  the  first 
of  these  losses  may  be  very  accurately  determined  by  referring 
to  tables  showing  the  amount  of  heat  radiated  under  different 
conditions  througrrvarious  thicknesses  of  walls,  windows,  doors, 
floors,  etc.  The  heat  loss  through  infiltration  differs  so  greatly 
in  various  sizes  and  constructions  of  buildings,  that  no  absolute 
rule  can  be  given.  The  allowance  to  be  made  for  heat  loss  is 
necessarily  the  result  of  experience  and  of  careful  tests  of  previous 
installation. 

Infiltration  or  leakage  is  produced  by  the  unbalanced  pressure 
of  the  column  of  heated  air  within  the  building,  and  that  of  the 
cold  air  without.  The  action  is,  in  principle,  precisely  like  that 
of  a  chimney.  The  difference  in  pressure  produced  can  be 
measured  in  inches  of  water,  and  increases  in  direct  proportion 
to  the  difference  in  temperature  between  the  air  within  the 
building  and  that  without.  Since  the  flow  of  air  is  proportional 
to  the  square  root  of  the  pressure,  that  amount  of  air  entering 
or  leaving  the  building  through  leakage  will  be  in  proportion  to 
the  square  root  of  the  difference  of  temperature.  The  effect  of 
this  leakage  is  as  evident  in  theory  as  it  is  noticeable  in  practice. 
The  air  which  escapes  from  the  building  is  naturally  the  very 
hottest  and,  therefore,  has  not  had  its  heat  fully  utilized,  while 
that  which  enters  along  the  floor  chills  the  air  at  the  lower  part 
of  the  building  perceptibly,  forming  a  cold  layer  of  air  which 
cannot  be  removed  except  by  a  positive  circulation  or  diffusion 
with  heated  air  such  as  may  be  secured  by  the  fan  system.  In 


FACTORY  HEATING  231 

large  machine  shops  and  foundries,  this  layer  of  cold  air  may 
frequently  be  found  to  extend  from  4  to  6  ft.  above  the  floor, 
while  overhead  there  is  a  volume  of  overheated  air  which,  if 
utilized,  would  heat  the  entire  building.  The  most  effective 
remedy  for  this  evil  is  to  maintain  a  slight  pressure  within  the 
building  by  means  of  a  fan  which  takes  a  portion  of  its  air  from 
without,  thereby  causing  a  displacement  and  removal  of  cold  air. 

Fan  System  and  Direct  Radiation  Compared. — In  either  fan  or 
direct  radiation  systems,  difficulty  is  likely  to  be  experienced 
from  the  rise  of  heated  air  which  forms  a  stratum  just  beneath 
the  roof.  In  machine  shops  and  foundries,  owing  to  their 
heights  and  to  the  great  amount  of  skylight  which  is  usually 
provided,  the  loss  occasioned  by  this  action  of  the  heated  air  may 
be  considerable,  and  its  prevention  is  a  serious  problem.  In 
direct  radiation,  where  the  air  currents  are  wholly  due  to  the 
difference  in  temperature,  the  attendant  loss,  which  is  relatively 
great,  is  unavoidable.  Practically,  the  only  way  in  which  this 
heated  air  can  be  made  use  of  is  by  placing  the  coils  next  to  the 
wall  near  the  floor,  and  allowing  the  heated  currents  to  pass 
upward  along  the  walls,  but  even  this  method  is  wasteful  from 
the  fact  that  it  heats  the  walls  unduly,  causing  a  loss  which  may 
usually  be  estimated  as  great  as  25  per  cent,  of  the  total  heat 
supply.  Pipes  near  the  walls  fail  to  properly  distribute  the  heat 
and  the  central  part  of  a  building  may  be  much  cooler  than  the 
sides.  The  fan  system,  however,  since  the  method  of  distributing 
the  air  is  entirely  mechanical,  affords  an  opportunity  for  utilizing 
its  heating  effects  to  the  very  best  advantage.  Various  methods 
of  distribution  have  been  devised  with  fan  system  whereby  the 
effect  of  a  rising  current  of  heated  air  is  almost  entirely  avoided. 
These  systems  in  general,  depend  upon  securing  diffusion  of  the 
heated  air  along  or  near  the  floor  line. 

Systems  of  Air  Supply. — The  method  of  distributing  the  air 
in  the  building  is  a  consideration  of  chief  importance.  The  usual 
methods  of  supplying  heated  air  are:  First,  to  take  the  air 
entirely  from  without,  and  force  it  directly  into  the  building 
through  distributing  ducts.  This  method  is  generally  known 
as  the  Plenum  System.  The  pressure  produced  in  the  building 
causes  a  continuous  exit  of  air  from  the  building,  either  through 
the  natural  openings  as  is  usually  the  case  in  factories,  or  through 
special  vent  openings  provided  for  the  purpose.  This  effectually 
prevents  the  entrance  of  cold  air  from  without. 


232     ENGINEERING  OF  SHOPS  AND  FACTORIES 

A  second  and  more  common  method  for  shop  buildings  where 
forced  ventilation  is  not  a  necessity,  is  to  draw  the  supply  of  air 
entirely  from  within  the  building  and  again  force  it  through  the 
distributing  ducts,  causing  a  continuous  circulation  of  the  air 
within  the  building.  This  often  has  an  advantage  over  the 
plenum  system  in  that  all  the  heat  supplied  to  the  air  is  effective 
for  heating.  This  method  is  especially  suitable  in  very  cold 
climates  but  can  be  used  only  where  gas,  fumes,  or  smoke  are 
not  generated  inside  the  shop. 

An  ideal  arrangement  is  a  combination  of  the  plenum  and 
return  systems,  and  this  should  be  used  wherever  possible.  By 


^ 


MACHINE  SHOP 


;.     n      •• 

BOILER  SHOP 


FIG.  124. — Fan  system  in  railway  machine  shop  at  Collinwood,  Ohio. 

this  method,  the  greater  portion  of  the  air  is  returned  to  the 
apparatus,  but  sufficient  air  is  continuously  taken  from  without 
through  a  fresh  air  connection  to  create  a  plenum  within  the 
building  and  prevent  the  inward  leakage  of  cold  air  along  the 
floor.  In  this  manner  the  natural  leakage  is  supplied,  not  by 
inflow  of  cold  air  through  crevices  around  the  doors  and  windows, 
but  by  air  passed  through  the  apparatus  and  heated  to  an  effect- 
ive degree.  This  combination  has  been  found  by  tests  to  be 
more  economical  than  air  returned  alone.  The  proper  amount 
of  air  to  be  introduced  from  without  is  determined  by  securing 


FACTORY  HEATING  233 

a  point  where  the  noticeable  inward  flow  of  air  around  the  doors 
or  windows  ceases.  If  the  plenum  is  carried  beyond  this  point, 
there  will  be  a  loss  due  to  unnecessary  heating  of  the  outdoor  air. 
Air  should  always  be  supplied  at  the  right  degree  of  humidity 
in  order  to  prevent  occupants  of  the  building  from  taking  cold. 
This  can  best  be  done  in  the  air  washing  process.  The  heating 
apparatus  and  fans  should  be  placed  at  one  side  of  the  building 
somewhere  near  the  center  of  its  length,  but  nearest  to  that  end 
which  may  at  some  future  time  be  extended. 

Systems  of  Air  Distribution. — There  are  several  systems  of 
distributing  the  heated  supply  of  air.  A  method  usual  in  public 
and  office  buildings  and  sometimes  employed  in  factories,  is  the 
vertical  duct  system  by  which  the  air  is  admitted  through 
vertical  ducts  or  flues  built  into  the  walls  and  opening  at  a  point 
about  8  ft.  above  the  floor.  Suitable  openings  are  supplied  at 
the  floor  line  for  the  air  that  is  forced  out.  By  this  method,  the 
heated  air  is  continually  forced  downward  as  it  cools,  and  the 
cold  air  is  always  removed  'at  the  floor  line.  In  some  cases  ducts 
in  the  walls  have  been  lined  with  hollow  brick,  but  later  experi- 
ence proved  this  to  be  not  only  unnecessary  but  undesirable. 

A  method  of  distribution  quite  similar  to  this  is  one  where  the 
air  is  first  blown  into  brick  ducts  underneath  the  floor.  From 
these  ducts  vertical  galvanized  iron  risers  are  arranged  along  the 
wall.  These  are  placed  so  as  to  blow  downward  and  away  from 
the  wall  at  a  height  of  about  8  ft.  from  the  floor.  These  outlets 
should  be  adjustable  so  that,  in  case  too  direct  a  draft  is  caused 
in  any  portion  of  the  building,  the  outlet  can  be  turned  in  some 
other  direction  where  the  air  current  will  not  be  objectionable. 

This  system  is  sometimes  modified  by  placing  the  outlets  close 
to  the  floor  and  blowing  downward  directly  along  the  floor. 
This  secures  a  perfect  diffusion  of  the  heated  air  at  the  floor 
line,  and  avoids  any  draft. 

Excellent  results  can  be  secured  by  the  use  of  overhead  piping, 
provided  it  is  not  placed  at  too  great  a  distance  from  the  floor 
The  chief  advantage  of  the  overhead  system  is  the  saving  in 
.first  cost,  since  on  account  of  the  high  temperature  and  velocity 
of  air  in  the  distributing  pipes,  a  great  amount  of  heat  can  be 
transferred  with  a  very  small  amount  of  material.  The  cost  of 
the  galvanized  iron  distributing  system  of  air  ducts  is  relatively 
small.  Circular  pipes  have  less  perimeter  for  a  given  area  than 
square  ones  and,  therefore,  require  less  material  to  make  them. 


234     ENGINEERING  OF  SHOPS  AND  FACTORIES 


They  should  always  be  galvanized.  The  best  results  are  se- 
cured with  outlets  from  12  to  18  ft.  above  the  floor  line.  Above 
this  height  it  is  preferable  to  use  drop  pipes  extending  down- 
ward along  the  columns,  where  they  will  not  interfere  with  travel- 
ing cranes.  Such  an  arrangement  of  overhead  piping  is  very 
frequently  employed  in  foundries,  while  in  large  machine  shops 
underground  ducts  are  nearly  always  preferable.  The  discharge 
openings  should  be  not  less  than  5  in.  in  diameter  and  the 
aggregate  area  of  all  the  openings  should  give  at  least  6  sq.  in. 
for  each  1000  cu.  ft.  of  building  contents,  so  that  air  within  the 
building  may  be  changed  two  to  three  times  every  hour.  Outlets 
should  be  about  30  ft.  apart,  and  the  total  area  of  all  the  openings 
should  be  about  25  per  cent,  greater  than  the  area  of  the  main 
supply  pipe.  Bends  in  ducts  or  branches  from  them  should 
always  be  made  with  gradual  curves  rather  than  sharp  angles 
to  avoid  obstructing  the  flow  of  air. 


GENERAL  PLAN.LOCOMOTIVE  REPAIR  SHOP 
PHILADELPHIA  AND  READING  R.  R.  CO. 


FIG.  125. — Heating  plant  in  railway  machine  shop. 

Another  system  which  has  proved  very  satisfactory  is  that  in 
which  a  distributing  air  return  duct  is  employed.  This  ap- 
proaches very  closely  in  principle  to  the  plenum  system  used  in 
public  buildings  and  is  a  combination  of  both  plenum  and  ex- 
haust systems.  This  may  be  best  described  by  referring  to  the 
heating  plant  at  the  Philadelphia  and  Reading  Railroad  shops  at 
Reading  (Fig.  125).  In  this  instance  several  separate  sets  of 
apparatus  have  been  provided,  placed  in  small  fan  houses  built 
at  intervals  at  either  side  of  the  building.  The  peculiar  feature 
in  this  installation  is  that  no  distributing  ducts  or  piping  for  the 
heated  air  are  used.  The  air  is  blown  directly  into  the  building 


FACTORY  HEATING 


235 


at  about  8  or  10  ft.  above  the  floor  through  an  outlet  branching 
in  three  directions.  The  distribution  is  affected  entirely  by  the 
return  vent  ducts  which  are  placed  at  frequent  intervals  along  the 
walls.  These  open  into  large  return  air  tunnels  which  are  pro- 
vided on  either  side  of  the  building,  and  serve  the  additional 
purpose  of  affording  a  convenient  place  for  locating  steam  and 
water  mains,  and  also  electric  light  and  power  cables. 

In  many  instances  an  elaborate  distribution  is  impracticable 
or  undesirable.  In  such  cases  a  centrally  located  discharge 
pipe  may  be  used.  From  this  point  the  air  is  blown  in  all  direc- 
tions, and  a  circulation  is  produced  by  an  exhaust  connection  to 
the  fan  inlet.  In  such  instances  very  effective  heating  has  been 
secured  even  where  it  was  required  to  blow  the  air  long  distances. 


riONAL   ELEVATION 


FIG.    126. — Foundry    heating    apparatus    with    only    small    amount    of 

distributing  pipe. 

A  good  example  of  such  a  system  may  be  found  in  the  foundry 
building  (Fig.  126)  of  the  General  Electric  Company  at  Schenec- 
tady,  which  is  one  of  the  largest  in  the  world  and  is  heated  in  a 
satisfactory  manner  with  a  few  large  branch  outlets.  Since  the 
plant  was  installed,  a  large  addition  has  been  made.  This  por- 
tion is  heated  by  a  branch  outlet  situated  200  ft.  from  the  further 
end  which  shows  how  thorough  distribution  may  be  secured  by 
forced  circulation. 

The  works  of  the  Warren  Featherbone  Company  at  Three  Oaks, 
Michigan,  gives  a  typical  installation  of  the  fan  system  to  a  group 
of  scattered  buildings,  and  is  remarkable  chiefly  for  the  distance 


236     ENGINEERING  OF  SHOPS  AND  FACTORIES 

to  which  the  heated  air  is  transmitted  from  the  apparatus  to  the 
various  buildings.  The  hot  air  piping  is  carried  entirely  out  of 
doors,  and  is  protected  by  a  wood  boxing  filled  with  sawdust. 
The  loss  of  temperature  in  passing  through  this  piping  is  de- 
termined by  test  to  be  only  5  degrees,  which  is  remarkably  small 
considering  the  length  and -exposure  ,pf  the  piping.  It  has  the 
advantage  of  a  central  location  of  apparatus  near  the  power 
house,  thus  utilizing  the  exhaust  steam  without  long  and  ex- 
pensive steam  piping,  and  minimizing  the  amount,  of  attention 
required. 

Advantages  of  the  Fan  System. — It  has  been  shown  that  a 
most  important  source  of  economy  with  the  fan  system  lies  in 
the  ability  to  secure  a  perfect  distribution  and  diffusion  of  heat 
and  by  the  production  of  a  plenum,  preventing  the  cold  air  from 
entering  the  building  and  settling  along  the  floors.  Besides  this 
the  temperature  is  much  more  easily  regulated  with  the  fan 
system,  with  separately  controlled  heater  sections,  than  with 
direct  radiation,  and  thus  a  great  loss  which  frequently  occurs, 
due  to  overheating,  is  prevented. 

Utilization  of  Waste  Heat. — Another  point  in  economy  is  the 
utilization  of  waste  heat.  By  far  the  most  common  form  of 
waste  heat  is  from  steam  engines  and  other  steam  driven  ma- 
chinery. The  ordinary  simple  engine  running  non-condensing 
has  a  water  rate  of  about  32  Ib.  per  horse-power  and  uses  only 
20  per  cent,  of  the  total  heat  of  steam  in  work  radiation,  leaving 
a  remainder  of  80  per  cent,  available  for  the  use  in  heating  appa- 
ratus, which  would  otherwise  be  wasted.  As  the  mean  effective 
pressure  in  the  ordinary  engine  cylinder  may  be  placed  at  40 
Ib.  per  square  inch,  an  increase  of  1  Ib.  per  square  inch  in  back 
pressure  reduces  the  effective  horse-power  of  the  engine  2J 
per  cent,  and  correspondingly  increases  the  cost  of  the  power 
production.  In  a  compound  engine  the  effect  of  back  pressure  is 
still  more  noticeable  since  the  mean  effective  pressure  referred  to 
the  low  pressure  cylinder  may  be  placed  at  about  30  Ib.  per 
square  inch;  each  pound  of  back  pressure  therefore  reduces  the 
power  of  the  engine  3J  per  cent.  It  is  therefore  evidently  un- 
profitable to  use  a  system  which  wrill  greatly  increase  the  back 
pressure  of  the  engine.  The  ordinary  system  of  direct  radiation 
used  in  shop  buildings  usually  cannot  be  operated  successfully 
without  placing  a  back  pressure  upon  the  engine  which  is  pro- 
hibitory. On  the  other  hand,  the  fan  system  heater  is  designated 


FACTORY  HEATING  237 

to  circulate  steam  at  very  low  pressure   and  can   be  operated 
successfully  with  J-lb.  pressure  on  the  engine. 

Air  Economizers. — An  air  economizer  is  employed  to  great 
advantage  at  the  plant  of  the  Cheboygan  Paper  Company,  where 
900  boiler  horse-power  of  live  and  exhaust  steam  is  required  in 
heating  the  rolls  and  beaters.  The  building  is  heated  by  the  fan 
system  in  connection  with  an  air  economizer,  and  a  system  of 
mechanical  draft.  This  makes  nearly  all  the  exhaust  steam  of 
the  plant  available  for  use  in  the  rolls  and  increases  the  economy 
and  heating  capacity  of  the  boilers  from  10  to  15  per  cent.  This 
system  illustrates  another  method  of  removal  of  the  steam 
directly  from  the  machinery  by  the  use  of  hoods  and  disk  fans. 
Sufficient  hot  air  must  be  introduced  into  the  building  to  take  the 
place  of  the  air  removed,  and  to  keep  the  building  warm,  other- 
wise condensation  would  occur.  The  above  system  of  heating 
with  air  economizer  is  in  successful  operation  in  many  places. 

Heating  with  Exhaust  Steam. — Where  condensing  engines  are 
used,  it  is  sometimes  questioned  whether  it  is  cheaper  to  run  them 
non-condensing  and  use  exhaust  steam  for  heating,  or  to  operate 
condensing  and  use  live  steam  for  heating  purposes.  The  water 
rate  of  a  compound  Corliss  engine  at  full  load  is  about  20  Ib.  per 
horse-power  non-condensing,  and  14  Ib.  condensing,  so  that  the 
water  rate  is  30  percent,  less  when  running  condensing  than  when 
non-condensing.  The  amount  of  heat  available  in  the  exhaust 
steam  when  running  non-condensing  is  about  80  per  cent. 
Hence,  we  see  that  the  saving  of  steam  running  condensing  is  only 
6  Ib.  per  horse-power  while  the  heat  available  in  the  exhaust 
steam  is  16  Ib.  per  horse-power  and  therefore  a  saving  of  10  Ib. 
of  steam  per  horse-power  could  be  made  by  operating  non-con- 
densing and  using  the  steam  in  the  heater  if  all  the  steam  available 
could  be  used.  There  would  also  be  saving  so  long  as  more  than 
38  per  cent,  of  exhaust  steam  was  utilized  in  the  heater.  With 
less  economical  engines,  the  saving  made  by  running  non-con- 
densing and  utilizing  the  exhaust  steam  is  greater. 

With  the  steam  turbine,  the  water  rate  increases  very  much 
more  rapidly  with  the  decrease  in  vacuum  (as  shown  by  an  in- 
crease in  the  number  of  inches  registered  on  the  vacuum  gauge) 
than  with  a  steam  engine.  A  steam  turbine  which,  with  28  in. 
of  vacuum,  has  a  water  rate  of  20  Ib.  of  steam  per  kilowatt  hour 
at  full  load  when  running  non-condensing  requires  50  Ib.  of  steam 
per  kilowatt  hour  at  full  load.  Hence  the  use  of  exhaust  from 


238     ENGINEERING  OF  SHOPS  AND  FACTORIES 

turbines  without  a  vacuum  is  economical  when  the  heating 
requirements  are  more  than  60  per  cent,  of  the  steam  consumption 
of  the  turbine  running  non-condensing. 

Other  sources  of  waste  heat  have  been  utilized  to  great  advan- 
tage by  means  of  an  air  economizer  in  connection  with  the  fan 
system  of  heating,  and  mechanical  draft,  and  the  waste  gases  from 
the  boilers,  burning  kilns,  gas  engine's,  etc.  The  heat  of  these 
gases  is  being  successfully  used  in  many  places  for  both  heating 
and  drying  purposes.  By  this  system  it  is  possible  to  reduce  the 
temperature  of  the  boiler  flue  gases  from  550  to  250  degrees,  there- 
by increasing  the  heating  capacity  and  economy  of  the  boilers 
approximately  15  per  cent.  The  saving  affected  by  the  utiliza- 
tion of  these  sources  of  waste  heat  frequently  pays  for  the  cost  of 
installation,  in  one  season's  operation. 

Flexibility  of  Operation. — The  fan  system  possesses  a  great 
advantage  over  direct  radiation  systems  in  its  flexibility  of  opera- 
tion. With  direct  radiation  a  building  heats  up  very  slowly,  and 
it  is  usually  necessary  to  maintain  a  normal  temperature  all 
night  in  order  to  have  it  sufficiently  warm  in  the  morning.  On 
the  other  hand,  the  fan  system  with  the  proper  amount  of  reserve, 
can  heat  a  building  up  in  a  short  time.  This  allows  the  building 
to  be  cooled  down  during  the  night  to  just  above  freezing-point, 
say  an  average  temperature  of  35  to  40  degrees. 

First  Cost. — Besides  these  advantages  in  economy  over  direct 
radiation,  there  is  usually  a  considerable  advantage  in  first  cost 
in  favor  of  the  fan  system.  This  is  due  to  the  compactness  of  the 
system,  requiring  fewer  connections  and  shorter  lengths  of  steam 
mains,  but  more  particularly  to  the  great  saving  in  amount  of 
radiating  surface  required  owing  to  its  greater  effectiveness  in  the 
fan  system.  A  determining  factor  in  the  rate  of  heat  trans- 
mission of  any  heating  surface  is  the  velocity  of  air  over  that 
surface.  This  can  be  shown  by  curves  or  chart,  exhibiting  the 
relation  between  air  velocities  and  heat  transmission.  In 
direct  radiation,  the  heat  is  transmitted  by  convection  currents 
and  radiation  only,  while  with  the  fan  system  an  air  velocity  over 
the  coils  of  1200  to  1500  ft.  per  minute  is  usual;  the  former  trans- 
mits only  from  2  to  2.6  B.T.U.  per  square  foot  per  hour  per 
degree  difference  in  temperature,  while  the  fan  system  heater, 
transmits  from  11.8  to  13.4  B.T.U.  per  square  foot  per  hour, 
per  degree  difference  in  temperature,  or  more  than  five  times 
as  much  as  direct  radiation.  Hence  a  correspondingly  smaller 


FACTORY  HEATING  239 

amount  of  radiating  surface  may  be  used,  which  more  than  off- 
sets the  additional  cost  of  fan,  engine  and  hot-air  piping. 

The  chief  points  of  superiority  of  the  fan  system  may  be 
summarized  as  follows: 

1.  Good  ventilation  regardless  of  exterior  conditions. 

2.  Uniform  and  proper  distribution  of  heat. 

3.  High  efficiency  of  heating  surface. 

4.  Greatest  economy  in  operation. 

5.  Utilization  of  exhaust  steam. 

6.  Prevention  of  cold  drafts  from  without  by  production  of  a 
plenum. 

7.  Independent  regulation  of  heating  and  ventilating  effects. 

8.  Great  flexibility  in  operation  to  suit  varying  conditions. 

9.  Ease  of  control  which  prevents  overheating. 

10.  Compactness  with  economy  of  space  and  low  cost  of  steam 
connections. 

11.  Good  drainage,  with  few  repairs. 

12.  Low  cost  of  installation. 

13.  Apparatus  capable  of  removal  to  another  plant  if  required. 

The  Vacuum  System. — The  evident  and  growing  need  of  a  heat- 
ing system  which  will  utilize  the  exhaust  from  condensing  en- 
gines and  steam  turbines  under  a  considerable  vacuum  has  led  to 
the  introduction  of  the  vacuum  fan  system  of  heating.  This 
system  competes  in  no  way  with  others,  but  simplifies  the  method 
of  application  and  enables  vacuum  to  be  secured,  otherwise 
impossible.  It  insures  at  all  times  a  perfect  circulation  of  the 
steam  in  the  heater  coils  and  maximum  economy  when  operating 
with  the  exhaust  from  engines  or  turbines  operating  with  high 
vacuum.  The  system  is  particularly  adapted  to  the  successful 
operation  of  several  heaters  widely  separated  and  well  removed 
from  the  central  source  of  steam. 

Roundhouse  Installation. — The  application  of  the  fan  system 
is  advantageous  in  the  heating  and  ventilating  of  locomotive 
roundhouses.  These  are  especially  difficult  to  heat  on  account 
of  the  large  volume  of  warm  air  carried  off  through  the  open 
smoke  jacks  which  act  as  ventilators.  A  great  deal  of  heat  is 
absorbed,  too,  in  the  melting  of  the  snow  and  ice  on  the  locomo- 
tives and  in  the  evaporation  of  the  moisture  thus  produced. 
Ample  ventilation  is  required  to  remove  the  smoke  and  steam 
produced  by  the  engine  and  this  necessarily  consumes  much  heat. 
The  air  is  drawn  directly  from  out  of  doors  and  after  passing 


240     ENGINEERING  OF  SHOPS  AND  FACTORIES 

through  the  coils  of  the  heater,  is  distributed  by  a  system  of  un- 
derground ducts  to  the  different  stalls  where  it  is  discharged  into 
the  pits  directly  beneath  the  engine.  Often  the  outlets  in  the 
pits  are  provided  with  adjustable  elbows  and  dampers  so  that 
the  blast  of  hot  air  can  be  directed  against  any  desired  part  of  the 
engine  or  closed  off  entirely.  More  frequently,  however,  outlets 
are  allowed  to  remain  open  at  all  tirries.  By  blowing  the  hot  air 
directly  underneath  the  engine,  the  snow  and  ice  are  melted  in  the 
shortest  possible  time  and  the  moisture  is  absorbed  by  the  hot, 
dry  air  wih  great  avidity.  The  distribution  of  the  heat  at  the 
floor  line  places  it  where  needed  and  permits  it  to  be  utilized  to 
the  fullest  extent  before  the  air  passes  out  of  the  building.  As 
the  air  is  taken  entirely  from  outdoors,  the  necessary  ventilation 
is  secured  at  all  times  and  a  plenum  is  produced  within,  which 
tends  to  counteract  the  cold  drafts  occasioned  by  the  frequent 
opening  of  the  doors. 

Application  to  Textile  Mills. — In  textile  mills  there  is  the 
additional  problem  of  securing  proper  humidity  together  with 
ventilation.  Operators  in  textile  mills  have  long  appreciated  the 
importance  of  correct  humidity  and  temperature  conditions  in 
the  spinning  and  weaving  processes.  While  these  requirements 
were  well  understood,  no  entirely  satisfactory  or  adequate 
method  has  heretofore  been  introduced  for  securing  the  de- 
sired effect.  These  conditions  which  have  such  an  important 
bearing  upon  the  textile  processes  are :  First,  the  humidity  which 
is  naturally  quite  insufficient  for  the  best  results  during  the 
greater  part  of  the  year,  especially  in  the  cold  weather  of  winter 
and  in  the  hot,  dry  weather  of  summer.  Second,  the  temperature 
which  should  be  maintained  at  from  70  to  75°,  requires  special 
heating  in  winter  and  cooling  if  possible  in  summer  when  the 
high  outside  temperature  augmented  by  the  weaving  and  spin- 
ning machinery  becomes  a  great  detriment.  Third,  ventilation, 
which,  though  not  so  important  as  the  others  commercially,  is 
imperatively  demanded  from  a  humanitarian  point  of  view  where 
so  many  women  and  children  are  required  to  work  in  a  com- 
paratively small  space.  In  order  that  the  best  results  may  be 
secured  in  a  cotton  mill,  the  air  must  contain  a  percentage  of 
moisture,  which  can  most  easily  be  provided  by  blowing  air  into 
the  shop  charged  with  the  proper  amount.  A  dry  atmosphere 
is  detrimental  to  the  manufacture  of  cotton  goods  in  that  it 
causes  a  great  deal  of  electricity  which  makes  the  fibers  separate, 


FACTORY  HEATING  241 

but  when  a  certain  amount  of  humidity  exists,  the  fiber  becomes 
more  adhesive  and  pliant,  and  consequently  the  yarn  becomes 
smoother,  stronger  and  softer. 

The  demand  for  a  betterment  of  these  conditions  has  led  to 
recent  improvements  in  ventilating  and  heating  textile  mills, 
one  of  the  very  latest  improvements  in  this  direction  is  a  system 
for  humidifying,  ventilating  and  heating.  The  apparatus  is 
composed  of  five  essential  elements,  the  tempering  coils,  the 
humidifier,  the  heater,  fan,  and  the  system  of  air  ducts. 

The  air'is  first  drawn  through  a  series  of  tempering  coils  con- 
trolled by  the  proper  temperature  for  humidifying:  thence,  it  is 
drawn  by  the  fan  through  the  humidifier  and  forced  through 
heater  coils  and  by-pass  where  sufficient  heat  is  imparted  to  it  to 
maintain  the  desired  temperatures  in  a  room.  By  this  arrange- 
ment the  control  of  humidity  is  absolute  and  may  be  varied  at 
will  between  any  desired  limits.  The  mechanism  is  exceedingly 
simple  and  relatively  inexpensive.  The  temperature  in  the  room 
is  under  absolute  control  without  affecting  the  volume  of  ven- 
tilation. A  uniformity  of  temperature  and  humidity  is  main- 
tained. When  the  air  is  taken  from  outdoors  it  is  washed  and 
purified  as  well  as  humidified.  In  this  way  fresh  air  is  constantly 
supplied,  enabling  the  operatives  to  work  in  a  pure  healthful 
atmosphere  under  all  conditions  of  weather. 

Fan  System  in  Paper  Mills. — In  cold  weather  great  trouble  is 
usually  experienced  in  paper  mills  from  the  condensation  pro- 
duced from  the  moisture  laden  air  coming  in  contact  with  the 
cold  roof  and  walls.  This  condensation  not  only  drops  back  on 
the  dry  paper  producing  blisters,  and  thus  injuring  the  product, 
but  causes  the  roof  boards  and  timbers  to  rot  out  quickly.  The 
most  practical  and  satisfactory  method  yet  devised  is  to  blow 
hot  air  into  the  building  just  over  the  machines.  Heated  air  is 
thrown  against  the  roof  and  walls  by  a  set  of  outlets,  while 
another  set  of  outlets  is  discharging  air  against  the  machines. 
The  first  set  of  outlets  keeps  the  roof  warm  while  the  air  from 
the  second  set  diffuses  the  steam  remaining  away  from  the 
machines  and  dissipates  it.  Air  supplied  is  always  drawn  from 
without,  and  an  exit  for  the  moisture  laden  air  is  provided  by 
louvres  or  ventilators  in  the  roof.  This  insures  a  rapid  absorp- 
tion and  removal  of  the  atmosphere. 

Fan  System  in  Paint  Shops. — In  paint  shops  it  is  desirable  to 
dry  paint  rapidly  and  it  is  necessary  to  avoid  drafts  which  agitate 

16 


242     ENGINEERING  OF  SHOPS  AND  FACTORIES 


FIG.   127. — Heating  plant  for  paint  shop  at  Sedalia,  Mo.     Complete  air 
distribution  to  avoid  drafts. 


FACTORY  HEATING  243 

dust  and  blow  it  about  the  building.  With  the  fan  system  the 
former  results  are  obtained  by  the  introduction  of  dry  air  from 
without,  and  the  latter  is  avoided  by  the  use  of  unusually  low 
air  velocities  and  special  arrangement  of  ducts.  In  the  fan 
system  of  paint  shop  heating,  a  combined  plenum  and  exhaust 
system  is  frequently  employed  with  most  gratifying  results. 
The  air  may  be  discharged  through  an  overhead  system  at  low 
velocities.  A  downward  circulation  is  produced  and  all  cold  or 
moist  air  is  removed  at  the  floor  line  by  exhausting  a  portion  of 
the  air  through  underground  ducts  opening  into  the  pit  under  the 
cars.  This  system  avoids  all  disturbing  air  currents  and  affords 
a  perfect  distribution  of  the  heated  air.  In  locations  where  a 
great  deal  of  smoke  and  dust  prevails,  a  system  of  air  purifying 
may  be  used  to  advantage.  The  rapidity  of  drying  secured  by 
the  fan  system  far  exceeds  that  obtained  by  any  other  method, 
owing  to  the  frequent  renewal  of  the  air  and  its  consequent 
greater  drying  effect  (Fig.  127). 

Steam  Heating. — Heating  by  direct  radiation  is  usually  slow  on 
account  of  the  long  lines  of  pipes,  unless  a  vacuum  circulation  is 
installed,  and  steam  pipes  are  likely  to  leak  and  fill  with  conden- 
sation. A  common  rule,  known  as  "  the  222  formulae  "  for  finding 
the  amount  of  radiation  surface,  is  to  supply  1  sq.  ft.  of  radiation 
for  every  2  sq.  ft.  of  window,  20  sq.  ft.  of  exterior  wall,  and  200 
cu.  ft.  of  building  contents.  The  sum  of  these  three  quotients 
will  be  the  total  required  area  of  radiation  surface. 

Modern  multi-story  shops  with  70  to  80  per  cent,  of  their  walls 
composed  of  glass,  should  have  1  sq.  ft.  of  radiation  for  every 
130  to  150  cu.  ft.  of  volume.  In  Northern  latitudes  with  mini- 
mum temperatures  of  10  to  20  degrees  below  zero,  1  sq.  ft.  of 
radiation  may  be  needed  for  every  75  to  100  cu.  ft.  The  amount 
provided  in  buildings  of  the  old  style,  with  less  window  area, 
where  1  ft.  of  radiation  was  enough  for  200  to  220  cu.  ft.  of 
building,  is  quite  insufficient  in  shops  of  the  modern  type. 

Another  approximate  rule  for  determining  the  required  number 
of  lineal  feet  of  1-in.  piping,  for  heating  by  live  or  exhaust  steam, 
when  air  is  taken  from  without,  is  to  divide  the  cubic  contents 
of  the  building  by  150,  and  the  resulting  number  is  the  number 
of  lineal  feet  required.  Again,  dividing  the  number  of  lineal  feet 
of  1-in.  piping  just  found,  by  70  gives  the  approximate  required 
horse-power  of  the  boiler. 

In  one-story  metal  working  shops  with  galleries  and  central 


244     ENGINEERING  OF  SHOPS  AND  FACTORIES 

traveling  crane,  where  heating  pipes  cannot  cross  the  central  open 
space  occupied  by  the  cranes  when  moving,  ducts  must  either  be 
placed  under  the  floors  with  risers  at  the  walls,  or  there  must  be 
a  double  line  of  metal  ducts  at  each  side,  worked  by  two 
separate  blowers.  In  multi-story  buildings,  the  blowers  and 
fans  are  usually  placed  in  the  basement,  with  one  or  more  risers 
or  stand  pipes  rising  to  the  upper  floors,  from  which  pipes 
branch  out  as  in  one-story  shops.  In  new  buildings  these  flues 
can  be  in  the  outer  walls,  this  arrangment  being  .quite  suitable 
for  such  shops  as  textile  mills. 

The  cost  of  steam  heat  installation  is  usually  $3  to  $4  per  1000 
cu.  ft.,  of  building,  or  60  to  80  cents  per  square  foot  of  radiation 
surface. 

Heating  by  Floor  Radiation. — A  system  of  heating  by  radiation 
from- the  floors  which  are  artificially  warmed,  was  introduced  a 
few  years  ago  in  a  shop  for  the  Morse  Chain  Company  at  Ithaca, 
N.  Y.  In  this  case,  hot  air  was  admitted  directly  to  the  building 
only  in  extremely  cold  weather,  but  at  all  other  times  the  shop 
was  warmed  wholly  by  heat  radiation  from  the  floor.  Steam 
pipes  1-in.  in  diameter  were  laid  crosswise  of  the  building  inside 
of  4-in.  pipes  buried  in  the  concrete  floors,  the  larger  pipe  being 
covered  with  J  in.  of  wearing  surface.  A  large  metal  working 
shop  in  Cleveland,  plans  for  which  were  made  partly  by  the  writer, 
is  heated  in  a  somewhat  similar  manner.  The  building  is  400 
ft.  long,  and  245  ft.  wide,  and  heaters  are  placed  in  four  pits 
below  the  floor  at  one  side  of  the  shop.  Hot  air  is  conveyed 
through  four  main  transverse  concrete  ducts  below  the  floor,  to 
openings  or  registers  22  in.  in  diameter,  in  the  base  of  the  columns. 
By  using  four  separate  heaters,  the  probability  of  a  general 
breakdown  is  small,  for  if  one  should  be  out  of  repair,  there 
would  still  be  three  in  operation.  Branches  from  the  main  ducts 
are  24-in.  tile  sewer  pipes.  The  floor  of  the  shop  is  concrete 
and  granolithic — a  type  which  is  often  objectionable  on  account 
of  its  transmitting  heat  rapidly  from  the  body  and  causing 
fatigue — but  in  this  case  with  heat  ducts  below  the  floor  to  warm 
it,  this  objection  is  removed. 


FACTORY  HEATING 


245 


TABLE   XXI.-WEIGHT   PER   LINEAL   FOOT   OF   GALVANIZED   PIPES     U.  S. 

STANDARD  GAUGE 

Weights  in  Pounds  Avoirdupois  per  Running  Foot 


Diameter 
of  pipe 

Square  feet 
per  running 
foot 

Number  of  gauge 

26 

24 

22 

20 

18 

16 

4 

1.13 

1.13 

1.47 

1.69 

1.97 

2.56 

3.10 

5 

1.39 

1.39 

1.80 

2.08 

2.43 

3.19 

3.82 

6 

1.65 

1.65 

2.14 

2.47 

2.89 

3.79 

4.54 

7 

1.91 

1.91 

2.48 

2.86 

3.34 

4.39 

5.25 

8 

2.18 

2.18 

2.83 

3.27 

3.81 

5.01 

6.00 

9 

2.44 

2.44 

3.17 

3.66 

4.27 

5.61 

6.71 

10 

2.70 

2.70 

3.51 

4.05 

4.72 

6.21 

7.42 

11 

2.96 

2.96 

3.85 

4.44 

5.18 

6.80 

8.14 

12 

3.22 

3.22 

4.18 

4.83 

5.63 

7.40 

8.85 

13 

3.48 

3.48 

4.52 

5.22 

6.09 

8.00 

9.57 

14 

3.74 

3.74 

4.86 

5.61 

6.54 

8.60 

10.28 

15 

4.01 

4.01 

5.21 

6.01 

7.01 

9.22 

10.86 

16 

4.27 

4.27 

5.55 

6.40 

7.47 

9.82 

11.74 

17 

4.53 

4.53 

5.85 

6.79 

7.92 

10.42 

12.45 

18 

4.87 

4.87 

6.33 

7.30 

8.51 

11.18 

13.36 

19 

5.14 

5.14 

6.68 

7.71 

9.00 

11.80 

14.11 

20 

5.40 

5.40 

7.02 

8.10 

9.45 

12.42 

14.85 

21 

5.59 

5.59 

7.26 

8.39 

9.78 

12.85 

15.36 

22 

5.92 

5.92 

7.70 

8.88 

10.35 

13.60 

16.25 

23 

6.18 

6.18 

8.04 

9.27 

10.81 

14.40 

17.00 

24 

6.45 

6.45 

8.38 

9.67 

11.30 

14.84 

17.71 

25 

6.71 

6.71 

8.72 

10.06 

11.74 

15.41 

18.41 

26' 

6.97 

6.97 

9.05 

10.45 

12.20 

16.00 

19.15 

27 

7.33 

7.33 

9.40 

10.85 

12.67 

16.62 

19.87 

28 

7.50 

7.50 

9.75 

11.27 

13.13 

17.26 

20.60 

29 

7.75 

7.75 

10.07 

11.63 

13.58 

17.81 

21.30 

30 

8.10 

8.10 

10.54 

12.17 

14.20 

18.62 

22.25 

31 

8.36 

8.36 

10.87 

12.54 

14.63 

19.20 

23.00 

32 

8.62 

8.62 

11.20 

12.93 

15.10 

19.84 

23.70 

33 

8.88 

8.88 

11.56 

13.34 

15.56 

20.42 

24  .40 

34 

9.15 

9.15 

11.90 

13.73 

16.00 

21.08 

25.18 

35 

9.41 

9.41 

12.23 

14.10 

16.48 

21.65 

25.85 

36 

9.67 

9.67 

12.57 

14.50 

16.91 

22.22 

26.60 

37 

9.93 

9.93 

12.91 

14.90 

17.40 

22.84 

27.30 

38 

10.19 

10.19 

13.25 

15.29 

17.81 

23.40 

28.00 

39 

10.46 

10.46 

13.60 

15.60 

18.31 

24.02 

28.70 

40 

10.72 

10.72 

13.95 

16.08 

18.76 

24.68 

29.50 

246     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE   XXI.— WEIGHT  PER  LINEAL   FOOT   OF   GALVANIZED   PIPES,    U.  S. 

STANDARD  GAUGE— Continued. 
Weights  in  Pounds  Avoirdupois  per  Running  Foot 


Diameter 
of  pipe 

Square  feet 
per  running 
'foot 

Number  of  gauge 

26 

24 

22 

<* 

20 

18 

16 

41 

10.98 

10.98 

14.27 

16.47 

19.20 

25.25 

30.20 

42 

11.24 

11.24 

14.60 

16.86 

19.61 

25.86 

30.90 

43 

11.59 

11.59 

15.06 

17.38 

20.30 

26.60 

31.80 

44 

11.85 

11.85 

15.40 

17.78 

20.74 

"27.25 

32.60 

45 

12.11 

12.11 

15.75 

18.17 

21.20 

27.90 

33.30 

46 

12.37 

12.37 

16.10 

18.55 

21.62 

28.43 

34.00 

47 

12.63 

12.63 

16.40 

18.95 

22.10 

29.00 

34.70 

48 

12.90 

12.90 

16.78 

19.35 

22.60 

29.70 

35.50 

49 

13.15 

13.15 

17.10 

19.72 

23.00 

30.25 

36.20 

50 

13.41 

13.41 

17.45 

20.12 

23.50 

30.90 

36.90 

51 

13.66 

13.66 

17.75 

20.49 

23.90 

31.40 

37.50 

52 

13.94 

13.94 

18.12 

20.97 

24.40 

32.00 

38.30 

53 

14.20 

14.20 

18.46 

21.30 

24.90 

32.66 

39.00 

54 

14.46 

14.46 

18.80 

21.69 

25.30 

33.20 

39.70 

55 

14.81 

14.81 

19.28 

22.22 

25.94 

34.10 

40.80 

56 

15.07 

15.07 

19.60 

22.61 

26.40 

34  .  65 

41.40 

57 

15.33 

15.33 

19.95 

23.00 

26.80 

35.21 

42.10 

58 

15.58 

15.58 

20.30 

23.37 

27.30 

35.84 

42.80 

59 

15.83 

15.83 

20.55 

23.74 

27.70 

36.40 

43.50 

60 

16.12 

16.12 

20.95 

24.18 

28.20 

37.00 

44.30 

62 

16.65 

16.65 

21.65 

24.97 

29.10 

38.20 

45.70 

64 

17.16 

17.16 

22.30 

25.74 

30.00 

39.50 

47.20 

66 

17.66 

17.66 

22.97 

26.49 

30.90 

40.60 

48.50 

68 

18.21 

18.21 

23.65 

27.31 

31.83 

41.80 

50.00 

70 

18.75 

18.75 

24.40 

28.12 

32.80 

43.10 

51.50 

72 

19.25 

19.25 

25.02 

29.92 

33.70 

44.30 

53.00 

74 

19.79 

19.79 

25.70 

29.68 

34.65 

45.50 

54.50 

76 

35.62 

45.77 

54.73 

78 

35.75 

46.96 

55.13 

80 

36.65 

48.16 

56.63 

82 

37.57 

49.40 

58.00 

84 

38.50 

50.60 

59.40 

86 

39.39      51.77 

60.77 

Heating  and  ventilating 

Ducts  to  18  in.  diameter,  26  gal. 
Ducts  19  to  29  in.  diameter,  24  gal. 
Ducts  30  to  39  in.  diameter,  22  gal. 
Ducts  40  to  49  in.  diameter,  20  gal. 
Ducts  50  to  70  in.  diameter,  18  gal. 
Above  70  in.  diameter,  16  gal. 


For  planing-mill  work 

Ducts  to  8  in.  diameter,  24  gal. 
Ducts  9  to  14  in.  diameter,  22  gal. 
Ducts  15  to  20  in.  diameter,  20  gal. 
Ducts  21  to  30  in.  diameter,  18  gal. 


FACTORY  HEATING 

TABLE.  XXII— CARRYING  CAPACITY  OF  PIPES 


247 


Cubic  feet 
of  air  per 
minute 

Velocities 

500 

600 

800 

1000 

1200 

1500 

1800 

2000 

2500 

3000 

3500 

4000 

200 

9 

8 

7 

7 

6 

6 

6 

6 

6 

6   6 

6 

400     13 

11 

10 

9 

8 

8 

7 

7 

6 

6   6 

6 

600 

15 

14 

12 

11 

10 

9 

8 

8 

7 

7 

6 

6 

800 

18 

16 

14 

13 

12 

10 

9 

9 

8 

8 

7 

7 

1,000 

20 

18 

16 

14 

13 

12 

10 

10 

9 

8 

8 

7 

1,200 

21 

20 

17 

15 

14 

13 

11 

11 

10 

9 

9 

8 

1,400 

23 

21 

18 

16 

15 

14 

12 

12 

11 

10 

9 

9 

1,600 

25 

23 

20 

18 

16 

15 

13 

13 

11 

11 

10 

9 

1,800 

26 

24 

21 

19 

17 

15 

14 

13 

12 

11 

10 

10 

2,000 

28 

25 

22 

20 

18 

16 

15 

14 

13 

12 

11 

10 

2,200 

29 

27 

23 

21 

19 

17 

15 

15 

13 

12 

11 

11 

2,400 

30 

28 

24 

21 

20 

18 

16 

15 

14 

13 

12 

11 

2,600 

31 

29 

25 

22 

20 

18 

17 

16 

15 

13 

12 

11 

2,800 

33 

30 

26 

23 

21 

19 

18 

16 

15 

14 

13 

12 

3,000 

34 

31 

27 

24 

22 

20 

18 

17 

15 

14 

13 

12 

3,200 

34 

32 

28 

25 

23 

20 

19 

18 

15 

15 

13 

13 

3,400 

36 

33 

28 

25 

23 

21 

19 

18 

16 

15 

14 

13 

3,600 

37 

34 

29 

26 

24 

21 

20 

19 

16 

15 

14 

13 

3,800 

38 

35 

30 

27 

25 

22 

21 

19 

17 

16 

15 

14 

4,000 

39 

35 

31 

28 

25 

22 

21 

20 

18 

16 

15 

14 

4,200 

40 

36 

32 

28 

26 

23 

21 

20 

18 

16 

15 

14 

4,400 

41 

37 

32 

29 

26 

24 

22 

21 

18 

17 

16 

15 

4,600 

42 

38 

33 

30 

27 

24 

22 

21 

19 

17 

16 

15 

4,800 

42 

39 

34 

30 

28 

25 

22 

21 

19 

18 

16 

15 

5,000 

43 

40 

34 

31 

28 

25 

23 

22 

20 

18 

17 

16 

5,200 

44 

40 

35 

31 

29 

25 

24 

2.2 

20 

18 

17 

16 

5,400 

35 

32 

29 

26 

24 

23 

21 

18 

18 

16 

5,600 

36 

33 

30 

27 

24 

23 

21 

19 

18 

17 

5,800 

37 

33 

30 

27 

25 

24 

21 

19 

18 

17 

6,000 

.... 

.... 

38 

,  34 

31 

28 

25 

24 

21 

20 

18 

17 

6,200 

38 

34 

31 

28 

25 

24 

21 

20 

18 

17 

6,400 

39 

35 

32 

28 

26 

25 

22 

20 

19 

18 

6,600 

39 

36 

32 

29 

26 

25 

22 

21 

19 

18 

6,800 

40 

36 

33 

29 

27 

25 

23 

21 

19 

18 

7,000 

.... 

.... 

40 

36 

33 

30 

27 

26 

23 

21 

19 

18 

7,200 

.... 

41 

37 

34 

30 

28 

26 

23 

21 

20 

19 

7,400 

41 

37 

34 

30 

28   27 

24 

21 

20 

19 

7,600 

42 

38 

34 

31 

28   27 

24 

22 

20 

19 

248     ENGINEERING  OF  SHOPS  AND  FACTORIES 

TABLE  XXII.— CARRYING  CAPACITY  OF  PIPES— Continued 


Cubic  feet 
of  air  per 
minute 

Velocities 

800 

1000 

1200 

1500 

•f* 

1800 

2000 

2500 

3000 

3500 

4000 

7,800 
8,000 
8,200 
8,400 
8,600 
8,800 
9,000 
9,200 
9,400 
9,600 
9,800 
10,000 
11,000 
12,000 
13,000 
14,000 
15,000 
16,000 
17,000 
18,000 
19,000 
20,000 
21,000 
22,000 
23,000 
24,000 
25,000 
26,000 
27,000 
28,000 
29,000 
30,000 
31,000 
32,000 
33,000 
34,000 
35,000 
36,000 

43 
43 

38 
39 
39 
40 
40 
41 
41 
41 
42 
42 
43 
43 
45 
47 
49 
51 
53 
55 
56 
58 
60 
61 
63 
64 
65 
67 
68 
70 
71 
72 
73 
75 
76 
77 
78 
79 
81 
82 

36 
36 
36 
36 
37 
37 
38 
38 
38 
39 
39 
40 
41 
43 
45 
47 
48 
50 
51 
53 
54 
56 
57 
58 
60 
61 
62 
63 
65 
66 
67 
68 
69 
70 
72 
73 
74 
75 

31 
32 
32 
33 
33 
33 
34 
34 
34 
35 
36 
36 
37 
39 
40 
42 
43 
45 
46 
47 
49 
50 
51 
52 
53 
55 
56 
57 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 

29 
29 
29 
30 
30 
30 
31 
31 
31 
32 
32 
32 
33 
35 
37 
38 
40 
41 
42 
43 
44 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
57 
57 
58 
59 
60 
61 

27 
28 
28 
28 
29 
29 
29 
30 
30 
30 
30 
31 
31 
34 
35 
36 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
56 
57 
58 

24 
25 
2* 
25 
25 
26 
26 
26 
27 
27 
27 
28 
29 
30 
31 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
42 
43 
44 
45 
46 
47 
47 
48 
49 
50 
50 
51 
52 

22 
22 
23 
23 
23 
24 
24 
24 
24 
25 
25 
25 
26 
28 
29 
30 
31 
32 
33 
34 
34 
35 
36 
37 
38 
39 
40 
40 
41 
42 
42 
43 
44 
45' 
45 
46 
47 
47 

21 

21 
21 
21 
21 
22 
22 
22 
22 
23 
23 
23 
24 
25 
27 
28 
28 
29 
30 
31 
32 
33 
34 
34 
35 
36 
37 
38 
38 
39 
39 
40 
41 
41 
42 
43 
43 
44 

19 
20 
20 
20 
20 
21 
21 
21 
21 
21 
21 
22 
23 
24 
25 
26 
27 
28 
28 
29 
30 
31 
31 
32 
33 
34 
34 
35 
36 
36 
37 
38 
38 
39 
39 
40 
40 
41 

«  • 











.... 

FACTORY  HEATING  249 

TABLE  XXII.— CARRYING  CAPACITY  OF  PIPES— Continued 


Cubic  feet 
of  air  per 
minute 

Velocities 

1000 

1200 

1500 

1800 

2200 

2500 

300C 

3500 

4000 

37,000 
38,000 
39,000 
40,000 
41,000 
42,000 
43,000 
44,000 
45,000 
46,000 
47,000 
48,000 
49,000 
50,000 
51,000 
52,000 
53,000 
54,000 
55,000 
56,000 
57,000 
58,000 
59,000 
60,000 
61,000 
62,000 
63,000 
64,000 
65,000 
66,000 
67,000 
68,000 
69,000 
70,000 
71,000 
72,000 
73,000 
74,000 

83 
84 
85 
86 
87 
88 
89 
90 
91 
93 
93 
95 
95 
96 
97 
98 
99 

76 

77 
78 
79 
79 
81 
82 
82 
83 
84 
85 
86 
87 
88 
89 
90 
90 
91 
92 
93 
94 
95 
95 
96 
97 
98 

68 
69 
70 
71 
71 
72 
73 
74 
75 
75 
76 
77 
78 
79 
79 
80 
71 
82 
82 
83 
84 
85 
85 
86 
87 
88 

62 
63 
63 
64 
65 
66 
66 
67 
68 
69 
70 
70 
71 
72 
73 
73 
74 
75 
75 
76 
77 
77 
78 
79 
79 
80 

59 
60 
60 

61 
62 
63 
63 
64. 
65 
65 
66 
67 
68 
68 
69 
70 
70 
68 
68 
69 
69 
70 
7i 
71 
72 
72 
73 
73 
74 
75 
75 
76 
76 
77 
77 
78 
78 
79 

52 
53 
54 

55 
55 
56 
57 
57 
58 
59 
59 
60 
60 
61 
62 
62 
63 
63 
64 
65 
65 
66 
66 
67 
67 
68 
68 
69 
70 
70 
71 
71 
71 
72 
73 
73 
74 
74 

48 
49 
49 
50 
50 
51 
51 
52 
53 
53 
54 
55 
55 
56 
56 
57 
57 
58 
58 
59 
60 
60 
60 
61 
62 
62 
63 
63 
63 
64 
64 
65 
66 
66 
66 
67 
67 
68 

44 
45 
46 
46 
47 
47 
48 
48 
49 
:.50 
50 
50 
51 
51 
52 
53 
53 
54 
54 
55 
55 
56 
56 
57 
57 
57 
58 
58 
59 
59 
60 
60 
61 
61 
61 
62 
62 
63 

42 
42 
43 
43 
44 
44 
44 
45 
46 
46 
47 
47 
48 
48 
49 
49 
50 
50 
51 
51 
52 
52 
52 
53 
53 
54 
54 
55 
55 
56 
56 
56 
57 
57 
57 
58 
58 
59 





.... 



••'•• 

250     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE  XXII.— CARRYING  CAPACITY  OF  PIPES— Continued 


Cubic  feet 
of  air  per 
minute 

Velocities 

•f* 

2200 

2500 

3000 

3500  4000 

75,000 
76,000 
77,000 
78,000 
79,000 
80,000 
81,000 
82,000 
83,000 
84,000 
85,000 
86,000 
87,000 
88,000 
89,000 
90,000 
91,000 
92,000 
93,000 
94,000 
95,000 
96,000 
97,000 
98,000 
99,000 
100,000 

79 

80 
81 
81 
82 
82 
83 
83 
84 
84 
85 
85 
86 
86 
87 
87 
88 
88 
88 
89 
89 
90 
90 
91 
91 
92 

75 
75 

73 
76 

77 
77 
78 
78 
79 
79 
79 
80 
80 
81 
81 
82 
82 
83 
83 
84 
84 
84 
85 
85 
86 
86 

68 
69 
69 
70 
70 
70 
71 
71 
72 
72 
73 
73 
73 
74 
74 
75 
75 
75 
76 
76 
77 
77 
77 
78 
78 
79 

63 
64 
64 
64 
65 
65 
66 
66 
66 
67 
67 
68 
68 
68 
69 
69 
70 
70 
70 
71 
71 
71 
72 
72 
72 
73 

59 
60 
60 
60 
61 
61 
61 
62 
62 
63 
63 
63 
64 
64 
64 
65 
65 
65 
66 
66 
66 
67 
67 
68 
68 
68 

CHAPTER  XXI 
AIR  WASHING  SYSTEMS 

Several  effective  systems  are  available  for  washing  and  purify- 
ing air  before  forcing  it  by  fans  to  different  parts  of  buildings. 
These  include  the  Carrier,  Webster,  Acme,  Kinealy,  and  others. 
All  are  much  alike  in  essential  principles,  though  they  differ 
somewhat  in  detail. 

The  chief  features  of  air  washing  and  humidifying  systems 
are  the  spray,  separator,  and  the  method  of  humidity  control. 
The  first  of  these  is  one  of  the  most  important  elements.  It  is 
essential  that  the  water  be  divided  as  finely  and  distributed  as 


FIG.  128. — Eliminator  plates. 

evenly  as  possible,  and  one  way  of  obtaining  these  results  is  by  a 
special  type  and  arrangement  of  nozzles.  The  centrifugal  force 
generated  by  the  rapid  rotation  of  water  in  a  nozzle  causes  the 
stream  to  burst  into  an  invisible  mist  upon  leaving  the  orifice. 
The  distribution  of  the  spray  from  simple  brass  nozzles  is  even 
and  practically  uniform  over  the  entire  area  of  discharge.  When 
dependence  is  placed  on  lateral  discharge,  the  necessarily  high 
velocity  of  the  air  through  the  chamber  so  disturbs  the  normal 
form  of  the  spray  that  an  even  distribution  is  impossible.  The 
sprays  may,  however,  be  distributed  in  great  numbers  over  the 
entire  area  of  the  chamber  and  the  direction  of  the  discharge 

251 


252     ENGINEERING  OF  SHOPS  AND  FACTORIES 

made  nearly  parallel  to  the  air  current.  In  this  way,  there  will 
be  no  undesirable  distortion  of  the  discharge  and  the  chamber 
will  be  uniformly  and  completely  filled  with  a  perfectly  atomized 
spray.  Pipe  fittings  should  be  either  galvanized  or  of  brass,  to 


BY-PASS  DAMPER 

REGULATED  BY 

THERMOSTAT 


ELEVATION 


•a 

j 

g 

•5 

*~.~~'\   *  ***;"*X  *'  )* 

^N^^ 

jo 

."   ••  ;"',--,    '     /'      *"'< 

*•!    1 

|i 

'!££$}&& 

| 

THER'MOSTAT 

FAN 

ii£ 

:  "CHAMBER  ''"'  Y 

Z 

'W'ELL" 

||  0. 

^'  *--i-'.  '  *fc*    ;  "*'    i 

5 

\    ! 

II  a) 

51- 

g>^t/P? 

-I 
ill 

-5- 

ifti 

£ 

L  L 

i- 

j 

~)PHMP 

^       '      STRA1NER.11TT? 

[MOTOR 

PLAN 

FIG.  129. — Air  purifier  and  humidifier. 

prevent  corrosion,  and  a  suitable  strainer  should  be  provided. 
The  design  of  the  nozzles  and  of  the  systems  should  be  such  that 
no  stoppage  or  choking  can  occur. 

Construction  of  Eliminator. — After  the  spray  water  has  per- 


AIR  WASHING  SYSTEMS  253 

formed  its  function  of  cleaning,  moistening  and  cooling  the  air, 
all  free  particles  of  moisture  and  impurities  should  be  removed; 
at  the  same  time,  no  excessive  resistance  must  be  offered  to  the 
air  passage  which  will  interfere  with  the  ventilation.  This  can 
be  accomplished  by  an  arrangement  of  baffle  plates,  placed 
nearly  vertical  and  parallel  to  each  other,  with  a  space  between, 
forming  a  series  of  unbroken  sinuous  passageways.  Each  baffle 
is  composed  of  a  number  of  bent  plates  fastened  together.  The 
plates  should  be  non-corroding  and  may  be  constructed  of  sheet 
copper  at  some  additional  cost.  Owing  to  their  form,  the 
plates  are  rigid  without  excessive  weight,  and  they  should  be 
fastened  together  in  a  substantial  manner.  The  eliminator 
should  be  self-contained  and  have  a  flange  connection  for  attach- 
ment to  the  spray  chamber  and  to  the  fan  casing.  It  should  be 
rigidly  braced  by  angle  irons  and  supported  on  a  galvanized 
structural  iron  foundation. 

Action  of  Eliminator. — The  first  portion  of  the  eliminator  is 
covered  with  a  sheet  of  running  water  precipitated  from  the 
spray  laden  air.  The  air  passing  through  this  portion  impinges 
upon  the  wet  surface  and  all  solid  particles  in  the  air  are  caught 
and  washed  away.  The  second  portion  contains  lip-like  pro- 
jections which  prevent  the  free  passage  of  water  across  the 
surface  and  form  vertical  gutters  down  which  the  water  flows. 
No  trace  of  free  moisture  will  be  found  in  the  air  after  passing 
through  the  eliminator,  even  with  high  velocities.  The  loss  in 
pressure  of  the  air  in  passing  through  the  separator  is  inappreci- 
able when  standard  proportions  are  used. 

Spray  Chamber. — The  spray  chamber  should  be  made  of 
heavy  galvanized  iron  throughout  and  stiffly  braced  on  the  out- 
side with  IJ-in.  angle  irons.  It  should  be  put  together  in 
flanged  sections  and  be  watertight. 

Pumps. — The  spray  system  may  be  operated  from  the  city 
pressure,  although  it  is  usual  to  pump  the  water  over  and  over 
again  until  it  becomes  unfit  for  use.  The  latter  plan  requires 
a  pump,  a  receiving  tank  with  settling  chamber,  a  strainer,  an 
automatic  supply  and  an  overflow.  A  centrifugal  pump  is 
convenient  for  it  can  be  made  nearly  noiseless  in  operation, 
and  may  be  belted  directly  from  the  fan  shaft  or  driven  by  a 
small  direct-connected  motor.  There  are  no  valves  to  wear  out 
or  become  clogged,  making  it  superior  to  a  piston  pump  for 
continuous  service. 


254     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Hygrodeik. — The  common  forms  of  hydrometers  make  it 
necessary  for  the  observer  after  reading  the  wet  and  dry  bulb 
temperatures,  to  refer  to  a  chart  and  calculate  the  relative 


FRESH  AIR  INLET 


o      o 


WITH    AIR    SPACE 


FIRST  FLOOR  PLAN 
FIG.  130. — Fan  system  in  a  cotton  mill. 

humidity.  Instruments  which  indicate  the  relative  humidity 
direct  are  unreliable;  the  hygrodeik  consists  of  wet  and  dry 
bulb  thermometers  mounted  in  such  a  position  that  with  the 


AIR  WASHING  SYSTEMS  255 

assistance  of  the  diagram  and  pointer,  the  reading  is  taken  with 
ease  and  accuracy.  They  are  made  in  various  styles,  ranging 
in  price  from  $7  to  $11. 

Gas  Heater. — The  adaptation  of  the  gas  heater  to  provide  for 
warming  the  air  entering  a  heating  and  ventilating  system 
represents  a  field  for  use  quite  distinct  from  those  employing 
steam  heated  radiating  coils.  Its  use  is  applicable  to  any  situa- 
tion where  economy  and  particularly  cleanliness,  minimum 
amount  of  apparatus,  and  automatic  operation  are  desirable 
features.  Reports  of  tests  read  before  the  American  Society  of 
Mechanical  Engineers  in  1905,  show  efficiency  of  gas-fired  steam 
boilers  to  be  seldom  in  excess  of  65  to  75°,  yet  this  can  be  ex- 
ceeded in  the  guaranteed  efficiency  of  the  heater  used,  which  may 
have  a  special  arrangement  for  the  return  of  a  portion  of  the  flue 
gases.  Besides,  the  direct-heat  furnace  is  much  cheaper  to 
install  than  a  gas-fired  boiler  and  steam  coil,  hence,  its  wide 
application  in  natural  gas  belts  or  where  fuel  gas  can  be  obtained 
at  ordinary  cost.  In  the  case  of  a  roundhouse  at  Parsons, 
Kansas,  the  design  insures  an  efficiency  of  90  per  cent,  at  full 
capacity  with  maximum  furnace  temperature  not  exceeding 
1200°,  and  a  minimum  temperature  of  waste  gases  about  400°. 

General  Arrangement. — The  apparatus  consists  in  general  of  a 
bank  of  vertical  boiler  tubes  expanded  at  top  and  bottom  into 
wrought-iron  boiler  plates.  The  space  between  the  tubes  can  be 
placed  below  the  floor  line,  and  divided  into  two  compartments. 
The  first  compartment  comprises  the  furnace  proper,  where  the 
gas  is  burned  under  general  conditions  described  later.  The 
other  portion  underneath  the  tubes  is  simply  an  exhaust  cham- 
ber for  the  waste  gases.  Above  the  tubes  is  located  a  single 
chamber  which  has  a  removable  sectional  cover  to  provide 
for  cleaning  and  inspection  of  tubes.  The  path  of  the  gases  is 
thus  upward  through  the  tubes  from  the  lower  to  the  upper  cham- 
ber, and  hence  downward  through  the  tubes  to  the  chamber 
underneath.  Above  the  tubes  is  an  exhaust  fan  which  handles 
waste  gases.  The  bank  of  tubes  is  enclosed  at  top,. bottom  and 
two  sides,  and  the  current  of  air  for  heating  purposes  is  drawn 
through  by  a  motor-driven  steel  plate  exhauster.  From  this 
fan  the  air  heated  to  a  temperature  of  about  170°  is  distributed 
through  galvanized  iron  ducts  in  the  usual  manner. 

Operation. — The  general  process  consists  in  first  burning  the  gas 
in  a  fire-brick  combustion  chamber  at  high  temperature  and  with 


256     ENGINEERING  OF  SHOPS  AND  FACTORIES 

very  small  excess  of  air,  and,  second,  mixing  this  small  volume 
of  hot  gases  at  high  temperature  with  a  larger  volume  of  the 
recirculated  products  of  combustion  at  the  relatively  low  tem- 
perature of  about  400°,  giving  a  resulting  temperature  not  ex- 
ceeding 1200°. 

Where  natural  gas  is  ,not  available,  a  gas  furnace  heating 
system  may  be  operated  quite  as  economically  as  a  steam  heat- 
ing system.  The  average  gas  producer  in  the  market,  using 


FIG.  131. — Fan  system  applied  to  a  cotton  mill. 

soft  coal,  will  give  an  efficiency  of  about  65  to  70  per  cent.  This 
would  give  a  combined  efficiency  of  gas  producer  and  gas  heater 
of  about  59  to  63  per  cent.  In  such  a  system  it  is  customary 
to  provide  for  the  utilization  of  the  exhaust  from  the  gas  engines 
which  may  be  introduced  into  the  lowest  chamber.  This  ex- 
haust alone  is  frequently  sufficient  to  heat  the  entire  building 
in  moderate  weather. 


CHAPTER  XXII. 
FACTORY  LIGHTING 

With  the  comparatively  recent  introduction  not  only  of  new, 
but  of  medium  sized  light  units,  the  art  of  illumination  may  be 
said  to  have  developed  into  the  science  of  illuminating  engi- 
neering. This  change,  with  the  far-reaching  possibilities  involved 
in  it,  is  as  yet  but  imperfectly  understood  by  the  public  at  large, 
and  time,  therefore,  will  be  required  to  demonstrate  the  tremen- 
dous advantages  to  be  derived  from  a  scientific  analysis  now 
attainable,  of  any  lighting  problem  as  against  the  cut-and-try 
method  of  arriving  at  a  solution  heretofore  in  common  use. 

Illuminating  engineering  when  applied  to  any  special  case, 
seeks  to  determine  the  light  best  adapted  for  the  purpose,  having 
due  regard  for  all  conditions,  and  embraces  such  factors  as  quan- 
tity, quality,  distribution,  continuity  of  service,  surroundings, 
costs,  etc.  The  large  variety  of  light  units  and  the  accessory 
apparatus  now  available,  render  a  determination  of  the  proper 
kind  of  unit  no  longer  a  perplexity  but  a  comparatively  simple 
matter.  One  of  the  hardest  things  the  illuminating  engineer 
has  to  contend  with,  however,  especially  in  interior  lighting,  is 
the  difficulty  in  setting  down  in  figures  the  total  economy — not 
merely  in  the  production  of  light  itself  but  also  that  made  pos- 
sible by  its  use — which  may  be  affected  by  a  modern  system  of 
lighting,  and  this  is  particularly  true  in  plants  already  equipped 
with  lighting  facilities,  inadequate  though  these  may  be  in  many 
cases. 

Among  the  several  items  contributing  to  the  total  gain  are  the 
following : 

1.  Decrease  in  cost  of  operation  and  maintenance  of  the  light- 
ing system,  or  increase  in  the  quantity  and  quality  of  the  light- 
ing for  the  same  cost. 

2.  Greater  accuracy  in  workmanship  with  consequent  lessen- 
ing of  defective  work. 

3.  Increase   in   production  with    accompanying   decrease   in 
cost. 

4.  Reduced  liability  to  accidents. 
17  257 


258     ENGINEERING  OF  SHOPS  AND  FACTORIES 

5.  Lessening  of  eye  strain. 

6.  More  cheerful  surroundings. 

It  will  be  seen  from  this  list  that  while  the  first  of  these  items  will 
readily  be  appreciated  by  everybody,  since  it  can  be  measured  in 
exact  money  values,  such  is  not  the  case  with  the  others;  in 
fac.t  the  very  existence  of  some  of  them  may  perhaps  be  a  novel 
thought  to  many  people  who  haVe  not  given  the  subject  of 
lighting  any  particular  study. 

Ten  years  ago  factory  electric  lighting  was  limited  to  the  car- 
bon filament  and  arc  lamp.  The  smaller  unit,  the  incandescent 
lamp,  is  still  very  useful  where  the  special  placing  of  small  lamps 
is  necessary.  Likewise  the  arc  lamp  is  useful  for  large  and  high 
areas  such  as  high  bays  of  large  machine  shops,  foundries  and 
the  like.  But  neither  of  these  serves  for  those  intermediate 
conditions  typified  by  large  rooms  with  ceilings  from  12  to  18  ft. 
in  height.  The  small  lamps  did  not  give  enough  light  unless 
used  in  large  numbers,  clusters  often  being  employed  which 
were  in  general  expensive  and  unsatisfactory.  The  arc  lamps 
in  such  cases  required  considerable  separation  and  provided 
poor  distribution,  not  a  very  satisfactory  illumination,  and 
usually  an  intense  light  in  the  line  of  vision. 

Within  the  last  few  years,  tungsten  lamps  of  various  sizes  have 
been  introduced,  with  candle-power  values  lying  between  and 
overlapping  those  of  the  enclosed  arc  and  the  carbon  filament 
lamps.  The  relative  efficiences  of  the  old  types  and  the  new 
tungsten  lamps  may  be  roughly  stated  to  be  2  to  1  with  the  old 
enclosed  arc  lamps,  and  from  3  to  1,  to  4  to  1,  with  the  carbon 
filament  lamps.  The  introduction  of  these  lamps  has  made 
possible  what  may  be  termed  a  new  era  in  factory  illumination, 
a  distinctive  feature  of  which  is  the  scientific  installation  of  the 
light  units,  suiting  each  to  the  location  and  class  of  work  for 
which  it  is  best  adapted.  This  was  formerly  impossible  with 
either  the  arc  or  carbon  filament  lamps. 

The  Candle-power  of  Units. — Before  the  introduction  in  recent 
years  of  medium  sized  units,  the  choice  of  the  size  of  unit  for  a 
given  location  was  often  no  choice  at  all.  In  many  cases,  due 
to  small  clearance  between  cranes  and  ceilings,  or  other  condi- 
tions making  it  necessary  to  mount  the  lamps  very  high  above 
the  floor,  but  one  size  or  type  of  unit  was  available,  the  carbon 
filament  lamp  in  the  former  and  the  enclosed  carbon  arc  lamp 
in  the  latter  case. 


FACTORY  LIGHTING  259 

For  low  ceilings  up  to  18  ft.,  the  use  either  of  the  carbon 
filament  or  arc  lamp  resulted  usually  in  anything  but  uniform 
illumination  over  the  working  plane,  and  often  produced  merely 
a  low  general  illumination  which  was  practically  useless  for  the 
individual  machines.  In  such  cases,  individual  lamps  had  to  be 
placed  over  the  machines.  With  this  arrangement,  relatively 
small  areas  are  lighted,  and  the  metal  shades  usually  employed 
only  serve  to  accentuate  the  "spot-lighting"  effect.  Such  a 
form  of  illumination  for  factory  work  is  unsatisfactory  and  in- 
efficient, but  as  stated,  was  in  many  cases  the  only  available 
scheme.  The  absence  of  lamps  of  the  proper  size  is  no  longer 
an  excuse  for  the  existence  of  such  conditions  in  industrial  plants. 

Relation  of  Lighting  Problems  to  Efficient  Management. — In 
factory  work,  efficiency  should  be  considered  from  at  least 
two  view-points,  in  the  one  case,  that  of  the  machine,  and  in  the 
other,  that  of  the  workman.  The  surrounding  conditions  under 
which  work  is  done  are  of  prime  importance  when  considering 
the  items  which  contribute  to  man-efficiency.  Among  these 
conditions  is  that  of  artificial  light.  Poor  illumination  produces 
a  bodily  and  mental  discomfort  which  seriously  affects  the  man 
and  his  work.  When  the  work  is  seen  with  difficulty,  when  the 
drawings  are  indistinct  and  the  surroundings  dim  and  gloomy, 
the  conditions  necessary  for  high  efficiency  are  lacking.  In 
those  instances,  therefore,  where  superior  illumination  im- 
proves the  physical  characteristics  which  tend  toward  a  better 
class  of  work  and  affords  more  cheerful  conditions,  it  should, 
without-  question,  be  provided. 

How  much  is  the  accuracy  and  general  quality  of  workmanship 
improved  by  good  instead  of  poor  lighting  results? 

How  much  does  the  stimulating  effect  of  bright  surroundings 
contribute  xto  cheerfulness  of  mind  and  alertness  of  action? 

How  many  mistakes  in  reading  figures  on  blueprints  or  on 
scales  are  due  to  poor  illumination? 

How  much  fatigue  and  eye  strain  and  impaired  vision  is 
caused  by  inferior  or  improper  lighting? 

To  what  extent  are  accidents  to  machinery  and  to  workmen 
decreased  by  having  good  instead  of  poor  illumination? 

It  is  difficult  to  answer  these  questions  in  a  definite  manner, 
but  no  one  familiar  with  industrial  conditions  will  take  excep- 
tion to  the  statement  that  good  illumination,  of  a  sufficiently 
high  intensity,  is  better  than  that  of  a  low  and  insufficient  inten- 


260     ENGINEERING  OF  SHOPS  AND  FACTORIES 

sity.  And  if  it  can  be  shown  that  the  actual  cost  of  good  illumi- 
nation is  small  compared  with  the  value  of  the  advantages 
secured,  then  inadequate  lighting  has  no  defence. 

The  practical  problems  involved  in  planning  a  lighting  system 
are  the  determination  of  the  factors  which  constitute  good  illumi- 
nation, by  careful  study  of  the  exact  conditions  under  which  the 
light  is  to  be  used,  and  the  adaptation  of  the  means  at  hand  to 
these  conditions.  Simple  as  these  problems  may  seem,  when 
carefully  analyzed,  they  will  be  found  to  be  much  more  intricate 
and  involved  than  might  be  expected. 

Importance  of  Good  Illumination  in  Factory  Work. — Adequate 
illumination  increases  output.  A  saving  of  even  several  minutes 
per  day  for  the  workmen  will  soon  pay  for  the  entire  cost  of 
installing  and  operating  a  suitable  factory  lighting  system.  The 
lighting  of  industrial  plants  is  one  of  the  factors  which  promotes 
efficiency.  Like  good  ventilation,  and  adequate  heating  sys- 
tem, or  cleanliness  and  neatness,  a  good  lighting  system  is  a 
necessary  item  in  maintaining  a  high  standard  of  workmanship. 
In  the  early  morning  and  late  afternoon  hours,  and  on  cloudy 
days,  many  factories  are  in  practical  darkness  as  far  as  daylight 
is  concerned.  No  one  single  factor  is  as  important  as  light, 
whether  natural  or  artificial,  as  an  aid  in  keeping  production  at  a 
high  efficiency  throughout  the  entire  working  day.  As  the  night 
turn  is  entirely  dependent  on  artificial  light,  the  importance  of 
factory  lighting  from  this  standpoint  cannot  be  overestimated. 

The  Relative  Cost  Factors  of  Light.— The  manager  is  perhaps 
most  concerned  with  the  cash  value  of  the  light.  How  much 
of  a  return  in  quantity  and  quality  of  work  will  result  from  the 
adoption  of  a  superior  system  as  compared  with  an  inferior  one, 
is  the  determining  question.  The  value  of  good  light  may  be 
placed  in  terms  of  time  saved  by  the  employee  in  performing  a 
given  amount  of  work,  in  the  greater  accuracy  and  perfection 
of  the  work,  in  the  saving  of  the  eyes  of  the  workmen,  and  in 
promoting  the  fa  ilities  for  better  and  more  work  by  providing 
brighter  and  more  cheerful  surroundings.  If  then,  better  light 
may  be  interpreted  in  terms  of  so  much  time  saved  by  the  em- 
ployee in  factory  operation,  the  equivalent  in  wages  of  this 
time  saved,  is  an  asset  of  the  improved  lighting  system. 

Assume  that  the  annual  operation  and  maintenance  cost 
for  a  typical  factory  bay,  16  ft.  by  40  ft.,  may  be  taken  as  $50. 
Assume  further  that  such  a  bay  will  accommodate  five  workmen 


FACTORY  LIGHTING  261 

whose  hourly  rate  averages  25  cents  and  whose  annual  wages 
equal  $3500.  By  adding  to  this  labor  cost  100  per  cent,  for  over- 
head burden  or  indirect  factory  expense,  the  gross  annual  cost  of 
the  bay  will  total  $7000.  Since  the  cost  of  operation  and  main- 
tenance of  the  lighting  is  $50,  it  is,  therefore,  only  0.7  per  cent, 
of  $7000,  or  0.7  per  cent,  of  the  gross  wages.  This  per  cent,  of 
the  wages  for  a  day  of  ten  hours  is  equivalent  in  time  to  a  little 
over  four  minutes.  It  is  not  unreasonable  to  assume  that  poor 
lighting  will  cost  at  least  one-half  of  this,  or  two  minutes  in 
wages.  Surely,  therefore,  if  good  light  enables  a  workman  to  do 
better  or  more  work  to  an  extent  equal  to  only  two  minutes  in 
wages  per  day,  the  additional  cost  of  good  lighting  over  inade- 
quate lighting  will  certainly  have  paid  for  itself. 

In  one  case  a  superintendent  said  that  his  men  lost  from  one 
to  two  hours  per  day  on  dark  days,  due  to  insufficient  light. 
This  meant  that  the  wages  paid  for  an  hour  or  two  each  day  was 
a  complete  loss  to  the  company.  Often,  therefore,  an  apparently 
expensive  lighting  equipment  will  prove  economical.  If  one 
kind  of  light  has  a  marked  advantage  over  another,  its  use  will 
result  in  better  or  more  work,  fewer  delays,  less  eye  strain,  and 
in  general,  greater  satisfaction. 

General  Requirements. — No  factory  can  afford  to  have  its 
employees  working  under  an  inadequate  illumination,  as  the 
losses  in  output  far  overbalance  any  supposed  economy  in  the 
energy  which  may  be  saved  by  such  means. 

Factory  lighting  should  be  reliable — unsteady  or  inreliable 
light  is  very  demoralizing. 

Specially,  factory  lighting  should  provide  the  following  fea- 
tures : 

1.  Adequate  light  for  each  employee. 

2.  Good  illumination  everywhere  on  the  working  plane,  and,  if 
possible,  when  the  floor  space  is  crowded  with  workmen  the 
illumination  should  be  of  a  satisfactory  intensity  without  regard 
to  the  location  of  the  work;  that  is,  the  illumination  should  be 
uniform  throughout  the  entire  shop. 

3.  Such  illumination  as  to  make  individual  carbon  filament 
lamps  unnecessary  except  in  very  special  cases.     Sometimes, 
however,  individual  lamps  on  machines  must  be  provided. 

4.  Illumination  provided  by  an  arrangement  and  size  of  units 
which  avoids  glare  due  to  light  from  an  intense  source  striking 
the  eye. 


262     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  preceding  requirements  should  be  fulfilled  by  a  type  of 
lamp  suitable  to  the  class  of  work  performed,  and  to  general 
physical  conditions,  such  as  clearance  between  cranes  and 
ceilings. 

Certain  Items  Bearing  on  Effective  Illumination. — The  inten- 
sity of  illumination  on  the  working  ^urf  ace  is  one  of  the  impor- 
tant items  which  determine  the  success  or  failure  of  any  lighting 
system.  The  eye  is  affected  by  the  intensity  of  the  light  reflected 
from  the  object,  rather  than  by  the  intensity  of  the  light  on  the 
object.  Hence  where  the  materials  or  parts  are  of  a  very  dark 
color,  more  light  may  be  required  for  a  certain  factory  space 
than  where  the  work  is  lighter  in  color.  For  this  reason  factory 
conditions  often  present  difficulties  in  the  matter  of  proper 
illumination  which  are  not  in  evidence  in  office  work,  or  in 
installations  of  a  different  class.  The  required  intensity  of  the 
illumination  for  various  kinds  of  work  is  an  item  impossible  to 
completely  specify.  It  has  been  found  that  2.5  foot-candles  on 
the  working  surface  is  sufficient  for  machine  work  where  practi- 
cally no  daylight  is  present.  In  other  cases  where  light  is  re- 
quired on  the  sides  of  objects,  and  where  the  work  itself  is  of  a 
nature  requiring  the  distinction  of  much  detail,  illumination 
intensities  of  five  foot-candles  and  over  are  sometimes  necessary. 

The  intensity  of  the  illumination  is  not,  however,  always  the 
most  important  feature.  In  some  cases  where  color  contrast  is 
largely  lacking,  an  increase  in  the  intensity  will  not  better  condi- 
tions. In  other  cases,  the  discrimination  is  based  almost  entirely 
on  shadow  effect.  In  finishing  a  die  for  a  punching,  dependence 
may  be  placed  almost  entirely  on  the  shadows  along  the  edges 
of  the  die  in  judging  of  the  exactness  of  the  fit.  In  an  instance 
of  this  kind,  a  drop  lamp  in  the  hands  of  the  workman,  who  can 
thus  control  the  direction  of  the  light,  will  be  far  better  than  any 
amount  of  overhead  illumination,  no  matter  what  the  intensity. 

Classification  of  Problems  in  Factory  Work. — A  classification, 
in  complete  form,  of  the  various  cases  included  under  this  head 
will  be  hardly  possible  of  successful  accomplishment.  Factory 
lighting  problems  might  be  grouped  according  to  surroundings, 
that  is,  whether  ceiling  and  walls  are  light  or  dark;  the  presence 
or  absence  of  line  shafting  and  belting;  the  work,  whether  flat, 
as  in  the  case  of  some  bench  work,  or  consisting  of  high  machines 
and  other  obstructions  to  light.  It  might  also  be  grouped 
according  to  the  height  of  ceiling  and  width  of  location,  although 


FACTORY  LIGHTING  263 

in  such  a  scheme,  two  spaces  of  the  same  dimensions  and  ceiling 
height  might  call  for  entirely  separate  illumination  plans  due  to 
other  conditions,  as  before  suggested.  For  these  reasons  a 
complete  classification  of  work  of  this  kind  is  hardly  possible 
or  even  advantageous.  It  has,  however,  been  found  convenient 
and  helpful  in  a  given  factory  to  separate  the  lighting  problems 
in  the  various  locations  according  to  ceiling  heights,  because  the 
size  of  lamps  and  their  spacing  depend  to  a  large  extent  on  this 
factor.  Low  ceilings  generally  call  for  small  or  medium  sized 
lamps,  while  large  lamps  are  more  applicable  to  the  higher  ceil- 
ings and  mounting  heights. 

The  Overhead  Method  of  Lighting. — A  system  of  lighting  in 
which  the  lamps  are  mounted  above  the  heads  of  the  workmen 
can  be  made  to  fulfill  most,  if  not  all,  of  the  requirements  better 
than  other  systems.  The  advantages  of  this  so-called  overhead 
system  as  compared  with  those  in  which  individual  carbon 
filament  lamps  mainly  are  depended  upon,  are  as  follows: 

1.  Such  a  system  can  be  made  to  furnish  good  illumination  at 
each  point  of  the  working  plane,  thus  permitting  work  to  be 
done  with  equal  comfort  at  any  point. 

2.  In  many  cases  it  can  be  made  to  furnish  a  light  of  such 
quality  as  practically  to  eliminate  the  necessity  for  individual 
lamps. 

3.  By  mounting  the  lamps  at  the  proper  height  and  making  a 
selection  of  the  proper  size,  glare  can  be  practically  eliminated. 

4.  The  eye  is  subject  to  a  harmful  effect  from  the  use  of  a 
single  lamp  placed  directly  over  and  close  to  the  work.     The 
bright  spot  of  light,  generally  of  too  high  an  intensity,  about 
the  work,  if  surrounded  by  a  region  of  comparative  darkness, 
causes  the  eye  to  become  fatigued  since  the  line  of  vision  is  con- 
tinually changing  from  the  bright  area  to  the  darker  surround- 
ings.    This  strain  on  the  eye  can  be  largely  avoided  if  the  entire 
working   surface   is   provided   with   a   uniform   illumination   of 
moderate  intensity. 

5.  Economy  in  maintenance  is  secured  as  compared  with  a 
system  with  large  numbers  of  drop  lamps. 

6.  The  appearance  is  neater  and  more  pleasing. 

Examples. — A  few  instances  of  the  satisfactory  results  ob- 
tained with  this  method  of  lighting  will  serve  to  show  with 
what  favor  it  is  viewed. 

In  one  factory  location  with  low  ceilings,   carbon  filament 


264     ENGINEERING  OF  SHOPS  AND  FACTORIES 

clusters  with  individual  incandescent  lamps  over  each  machine 
had  been  in  service.  A  system  of  100-watt  tungsten  lamps 
was  installed,  practically  all  individual  lamps  being  removed 
from  the  lathes  and  other  machines.  The  whole  appearance 
was  made  more  cheerful.  The  manager  stated  that  the  problem 
of  men  desiring  to  be  transferred  to  other  departments  on 
account  of  the  darkness,  was  solved.  Some  of  the  workmen 
were  overheard  to  say  that  tools  and  machine  parts  were  found 
which  up  to  that  time  had  been  lost  in  corners  due  to  the  dark 
surroundings,  the  shop  receiving  practically  no'  daylight  and 
therefore  having  been  constantly  in  partial  darkness. 

In  another  instance  where  tungsten  lamps  replaced  a  poor 
system  of  very  large  units,  supplemented  by  individual  lamps, 
the  superintendent  stated  that  on  many  days,  because  of  insuf- 
ficient light  in  the  early  morning  and  the  late  afternoon  hours, 
his  workmen  lost  one  and  one-half  hours  per  day.  This  condi- 
tion was  entirely  changed  by  installing  the  overhead  system. 
Practically  all  drop  lamps  were  removed.  In  still  another 
factory  location  a  superintendent  blamed  defective  work  to 
inadequate  light.  He  stated  that  he  had  experienced  great 
difficulty  in  retaining  a  good  class  of  help.  Large  tungsten 
lamps  transformed  the  dark  and  dingy  location  to  one  of  cheer- 
ful and  pleasing  appearance,  and  put  an  end  to  complaints. 

Another  factory  location  had  been  in  almost  complete  darkness 
as  far  as  overhead  lighting  was  concerned.  The  almost  humor- 
ous statement  was  made  upon  the  installation  of  a  good  over- 
head system,  that  the  men  did  not  wear  out  their  shoes  as  fast 
as  formerly — meaning  that  the  matter  of  getting  around  had 
been  complicated  by  their  stumbling  against  the  loose  iron  and 
material  which  had  been  allowed  to  accumulate  on  the  floor 
when  the  illumination  was  so  poor.  An  inspection  of  the  place 
after  the  new  system  was  installed  showed  it  to  be  in  perfect 
order  and  the  floor  space  neat  and  clean.  Much  satisfaction 
was  evidenced  by  the  workmen. 

The  substitution  of  an  overhead  system  will  promote  a  higher 
efficiency  of  production,  as  well  as  greater  cheerfulness  and  a 
better  spirit  among  the  workmen,  which  though  difficult  to 
express  in  money  value,  forms  a  distinct  feature  in  the  promo- 
tion of  good  and  efficient  workmanship. 

Glare. — One  of  the  most  pernicious  effects  of  improperly 
arranged  lamps  is  the  glare  produced  by  a  source  of  considerable 


FACTORY  LIGHTING  265 

brilliancy  when  unshielded  from  the  eye.  In  factory  work  the 
points  which  have  a  large  bearing  on  the  glare,  may  be  noted 
under  the  four  following  divisions: 

1.  Mounting  Height  of  Lamp. — As  a  general  rule,  it  is  best  to 
mount  all  lamps  well  out  of  range  of  vision.     The  argument  that 
the  lamps  should  be  close  to  the  work  for  the  purpose  of  gaining 
the  greatest  effectiveness  from  the  lamps  is  poorly  founded, 
since  the  increase  in  intensity  by  mounting  them  low  may  be 
more  than  offset  by  the  evil  effect  on  the  eye  produced  by  lamps 
mounted  in  the  line  of  vision. 

2.  Size  of  Lamps. — The  size  of  lamps  has  much  to  do  with 
glare.     It  has  been  found  that  where  the  ceiling  is  low  a  small 
lamp  is  not  nearly  so  trying  to  the  eye  as  a  large  one. 

3.  Spacing  of  Lamps. — The  spacing  has  a  certain  bearing  on 
the  glare,  since  the  closer  the  lamps  the  smaller  may  be  their 
size  to  provide  a  given  intensity. 

4.  Type  of  Reflectors  Used. — While  modern  reflectors  have, 
as  one  of  their  greatest  claims,  the  resulting  increase  in  efficiency 
of  light  distribution,  the  protection  afforded  in  shielding  the  eye 
from  the  lamp  filament  is  also  a  very  important  item. 

Shielding  Effect  of  Girders. — Very  often  in  factory  construc- 
tions, glare  may  be  much  reduced  by  mounting  the  lamps  so 
that  they  are  protected  by  some  feature  of  the  building  con- 
struction. Thus  in  the  room  shown  in  Fig.  132,  the  girders 
afford  an  excellent  protection  for  the  eye,  while  in  that  shown 
in  Fig.  133,  the  lamps  are  all  visible  down  the  aisle  whenever  a 
workman  looks  up  from  his  work. 

Selection  of  Lamps. — The  selection  of  lamp  units  best  adapted 
to  factory  conditions  and  their  most  advantageous  installation 
are  two  essential  factors  of  shop  lighting.  The  questions  in- 
volved are:  proper  number  and  size  of  units;  their  best  arrange- 
ment; economy  in  operation;  relative  first  cost,  and  installation 
costs. 

Number  of  Lamps  per  Unit  of  Floor  Space. — On  this  item 
depends  the  realization  of  a  uniform  and  satisfactory  distribu- 
tion of  the  light.  Care  should  be  taken  to  choose  the  number 
of  units  per  unit  of  floor  space,  which  will  furnish  a  sufficiently 
uniform  illumination  to  meet  the  important  condition,  that 
work  can  be  performed  at  any  point  on  the  floor  without  regard 
to  location.  The  next  step  will  be  that  of  selecting  a  size  and 
type  of  unit  which,  with  correct  spacing,  will  furnish  an  illumin- 


266     ENGINEERING  OF  SHOPS  AND  FACTORIES 


FIG.  132. — Shop  interior  at  night.     Vertical  surfaces  well  illuminated. 


FIG.  133. — Shop  interior  at  night. 


FACTORY  LIGHTING  267 

ation  of  sufficient  intensity.  An  example  will  illustrate  this 
point. 

25o-Watt  versus  loo-Watt  Units. — A  large  area  was  to  be 
lighted,  and  250- watt  tungsten  lamps  provided  in  such  numbers 
as  to  give  a  uniform  and  sufficient  intensity  of  illumination, 
appeared  desirable.  The  use  of  this  fairly  large  unit  would  have 
resulted  in  a  somewhat  low  first  cost  of  installation,  the  number 
of  lamps  per  unit  area  being  small.  There  were  so  many  work- 
men in  each  bay,  however,  that  men  located  at  certain  positions 
with  respect  to  the  lamps  would  have  worked  to  a  disadvantage 
because  of  marked  shadows.  It  was  important  that  work  be 
done  with  ease  at  any  point  of  the  floor  space.  In  this  par- 
ticular instance,  carbon  filament  lamps  had  been  used  for  years 
as  drop  lights  over  each  bench.  With  repeated  shifting  of  the 
work  a  continual  adjustment  of  these  drop  lights  was  necessary. 
This  maintenance  expense  was  considered  sufficiently  large  to 
be  a  factor  in  the  substitution  of  an  overhead  lighting  system 
and  the  subsequent  removal  of  all  drop  lights. 

Here  the  use  of  nine  100- Watt  tungsten  lamps,  per  standard 
25  by  25-ft.  bay,  rather  than  four  250-watt  lamps,  produced  a 
satisfactory  result.  It  should  be  noted  that  the  choice  of  the 
number  of  units  per  bay  depended  on  the  furnishing  of  light 
equally  good  in  every  direction  at  any  point  in  the  bay.  The 
use  of  the  250-watt  lamps  would  have  resulted  in  a  distribution 
as  uniform,  and  an  intensity  equally  great,  without  fulfilling 
the  main  requirement  in  the  matter  of  direction,  which  in  this 
case  was  important. 

Size  of  Lamps. — At  present  the  size  of  units  is  a  much  larger 
factor  than  ever  before.  If  the  ceiling  height  is  low,  say  12  ft. 
or  under,  the  use  of  arc  lamps  is  objectionable  because  of  their 
relatively  high  candle-power;  and  besides  the  glare,  the  lamps 
cannot  be  used  economically  in  sufficient  numbers  to  provide 
uniform  light  distribution.  Here,  medium  sized  units  have  the 
advantage,  and  60-watt  and  100-watt  tungsten  lamps  have 
been  used  successfully. 

For  bays  of  40  to  60  ft.,  in  height,  500- watt  tungsten  lamps 
may  be  used.  For  intermediate  ceilings  from  12  to  18  ft.,  in 
height,  lamps  of  the  100  to  400-watt  sizes  seem  best  adapted. 

Mounting  Height  of  Units  Above  Floor. — In  factory  work 
the  mounting  height  of  lamps  will  often  be  governed  by  the 
details  of  building  construction  and  the  interference  of  cranes. 


268     ENGINEERING  OF  SHOPS  AND  FACTORIES 

All  units  should  be  mounted  so  as  to  be  out  of  the  range  of  vision. 
This  condition  may  be  interpreted  in  several  ways.  The  glare 
from  lamps  will  not  be  so  noticeable  to  workmen  who  constantly 
look  down  at  their  work,  as  when  the  eye  is  for  the  most  part 
directed  along  the  horizontal.  Again  a  small  lamp  in  the  line 
of  vision  will  not  be  so  annoying  a^s  a  large  one.  One  solution, 
when  the  lamps  must  necessarily  :be  mounted  low  with  respect 
to  the  floor,  will  be  to  use  smaller  lamps  in  larger  numbers. 

Glare  is  probably  of  less  importance  in  factory  work  than  in 
offices,  but  is  harmful  nevertheless.  The  glare  from  rays  of 
excessive  brightness  should  be  avoided  because  it  lowers  the 
sensitiveness  of  the  eye.  The  intensity  of  the  illumination  on 
the  work,  while  possibly  sufficiently  high  under  other  conditions 
with  lamps  properly  placed  and  shielded,  may  seem  to  be  insuf- 
ficient, due  to  this  reduction  of  sensitiveness.  From  the  physical 
standpoint,  the  effect  of  glare  and  the  subsequent  eye  strain 
is  an  evil,  and  it  is  evident  that  a  workman  to  be  of  the  most 
value,  should  be  surrounded  by  the  most  advantageous  condi- 
tions for  promoting  rapidity  and  accuracy  in  his  work. 

Illumination  of  Vertical  Surfaces. — Another  important  feature 
connected  with  the  mounting  height  is  the  furnishing  of  light 
at  an  angle,  so  as  to  illuminate  the  side  of  the  tool  or  piece  of 
work.  The  point  at  which  the  tool  is  making  a  cut  may  require 
light  from  an  angle  rather  than  from  a  point  directly  overhead. 
For  a  given  spacing  of  lamps,  the  higher  they  are  mounted,  the 
more  concentrating  must  be  the  reflector  to  produce  the  highest 
efficiency  of  horizontal  illumination  on  the  working  surface. 
This  illumination  on  the  horizontal  surface  may  not,  however, 
be  the  greatest  feature  of  importance.  One  way  to  secure  more 
illumination  on  the  side  of  machines  is  to  lower  the  lamps  and 
use  more  broadly  distributing  reflectors,  so  that  the  light  is 
directed  sidewise  as  well  as  downward.  On  the  other  hand,  if 
the  lamps  are  mounted  too  low,  they  become  objectionable 
by  being  in  the  line  of  vision  when  a  man  looks  up  from  his 
work.  Thus,  in  one  instance  where  the  maximum  possible 
mounting  height  was  13  ft.  6  in.,  it  was  found  desirable  to  place 
the  lamps  at  this  height  to  avoid  glare;  the  side  lighting  was 
secured  by  using  broader  distributing  reflectors  and  somewhat 
larger  lamps  than  ordinarily  would  have  been  necessary,  thus 
bringing  up  the  horizontal  intensity  to  the  same  value  as  with 
the  more  concentrating  reflectors  and  smaller  lamps,  and  at  the 


FACTORY  LIGHTING 


269 


same  time  providing  the  necessary  side  light  for  the  vertical 
surfaces. 

Reflectors  for  Uniform  Illumination.  —  Uniformity  of  the  illumi- 
nation on  the  working  surface  generajly  refers  to  the  illumin- 
ation on  the  horizontal  planes,  similar  to  a  bench  or  a  table. 
Uniform  intensity  of  illumination  over  the  entire  bench  or 
floor  surface  of  a  room  is  generally  looked  upon  as  an  advantage 
in  a  lighting  system,  and  is  sometimes  the  only  factor  considered. 

Reflectors  or  shades  have  been  made  for  two  purposes.  One 
object  is  to  shield  the  direct  rays  of  the  lamp  from  the  eyes,  the 
other  being  to  redirect  the  light  from  the  lamp  in  the  most  use- 
ful and  effective  direction.  In  so  far  as  this  scientific  side  of 
reflectors  is  concerned,  they  are  now  designed  so  as  to  furnish 
fairly  definite  results.  Rules  for  the  use  of  such  reflectors  call 
for  a  certain  relation  between  the  spacing  of  lamps  and  their 
mounting  height,  if  uniform  downward  light  over  the  entire 
working  surface  is  desired.  For  example,  one  type  of  reflector 
calls  for  a  spacing  of  lamps  equal  to  0.7  of  the  mounting  height 


9  Ft 

/ 

\ 

s^Ft. 

V 

V 

/    , 

A 

4     I 

"V 

/ 

^v 

t/ 

NX 

1     6 

^^s 

"zp 

~            N> 

--^^e* 

2  —  J 

^-^^ 

^f^ 

im 

( 

FT8          * 

12  F 

t/6  In. 

*•  3 

FIG.  134. — Variation  in  intensity  of  illumination,  with  various  mounting 

heights. 

above  the  floor.  If  this  relation  between  spacing  and  mounting 
is  followed,  uniformity  of  the  illumination  on  the  plane  assumed, 
may  be  expected,  although  other  effects  such  as  ceiling  reflec- 
tion may  tend  to  vary  the  resulting  intensity.  In  case  this 
relation  is  violated  by  mounting  the  lamps  either  higher  or  lower 
than  called  for  by  rules  which  consider  uniformity  of  the  down- 
ward light,  the  resulting  illumination  on  the  working  surface  may 
depart  very  radically  from  a  condition  of  uniformity. 

Test  for  Uniformity. — The  effect  on  this  illumination  caused  by 
variations  in  the   mounting  heights  is  indicated  by  Fig.  134. 


270     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  lower  curve,  marked  with  a  mounting  height  of  12  ft.  6  in.} 
shows  an  approximate  uniformity  of  the  illumination.  The 
remaining  curves  show  the  effect  on  the  intensity  of  the  illumina- 
tion at  the  same  locations  when  the  lamps  and  reflectors  are 
lowered.  If,  then,  uniformity  of  the  illumination  is  desired, 
such  rules  as  are  indicated  by  the  various  reflector  companies 
for  the  spacing  and  mounting  of  lamps  for  a  given  reflector, 
should  be  adhered  to. 

Value  of  Light  Ceilings. — With  a  light  ceiling,  the  reflection 
of  that  portioni  of  the  light  which  passes  through  the  reflector 
to  the  ceiling,,  and  which  is  added  to  the  light  directed  down- 
ward from  the  reflectors,  is  a  factor  in  building  up  the  intensity 
of  the  illumination  on  the  working  surfaces.  In  a  case  of  this 
kind  uniform  illumination  is  obtained  by  the  use  of  almost  any 
reflector  whether  designed  for  the  purpose  or  not,  provided  the 
lamps  are  fairly  close  together.  In  fact,  tests  indicate  that  if 
lamps  without  any  reflectors  whatever  are  installed  in  a  room 
with  a  particularly  light  ceiling,  fairly  uniform  illumination  will 
result.  Under  such  a  condition,  however,  the  bad  effect  of  the 
unshielded  lamps  will  call  for  reflectors  of  some  kind.  It  should 
also  be  stated  that  while  a  uniform  light  distribution  may  result 
where  no  reflectors  are  used,  the  intensity  of  the  illumination 
when  measured  on  the  working  plane  may  be  increased  by  as 
much  as  60  per  cent.,  by  the  use  of  efficient  reflectors.  This  is 
due  to  the  utilization  of  the  horizontal  rays  of  light  which  pre- 
dominate in  the  bare  tungsten  lamp,  whereas  the  most  effect- 
ive light  rays  for  factory  work  are  those  which  are  directed 
downward. 

Lighting  Circuits. — The  matter  of  suitable  lighting  circuits 
is  an  important  consideration.  Some  units  are  adapted  to  direct 
current  only,  others  operate  most  favorably  with  certain  fre- 
quencies of  alternating  current.  All  units  to  be  most  effective 
should  be  supplied  with  constant  voltage.  In  factory  work, 
the  power  load  will  nearly  always  be  found  to  exceed  that  for 
lighting.  With  the  lighting  and  power  circuits  separate,  it  is 
easier  to  maintain  the  voltage  constant  on  the  lamps. 

Switch  Control. — The  switch  control  of  the  lamps  in  any  light- 
ing system  is  of  importance,  especially  where  large  numbers 
of  small  or  medium  sized  units  are  used.  That  method  of  con- 
trolling the  lamps  is  most  economical  in  which  the  interest, 
depreciation,  and  maintenance  involved  in  the  first  cost  of  the 


FACTORY  LIGHTING  271 

installation  of  switches  and  their  attendant  wiring,  does  not  ex- 
ceed the  cost  of  the  energy  saved  by  their  use  in  being  able  to 
turn  out  the  lamps  which  are  not  needed.  Too  great  refine- 
ment in  the  placing  of  switches  may  result  in  a  first  cost  in  excess 
of  the  saving  through  their  use.  Particularly  is  this  the  case 
where  the  factory  receives  little  daylight,  artificial  light  being  re- 
quired at  all  times.  Here,  if  the  number  of  workmen  is  great, 
practically  all  the  lamps  will  be  needed  all  the  time,  and  too 
great  refinement  in  switch  control  is  not  warranted.  In  prac- 
tice, however,  it  will  usually  be  found  advisable  to  install  a 
considerable  number  of  switches,  as  their  cost  is  low  in  com- 
parison with  that  of  the  energy  saved  by  the  ability  to  turn  off 
the  lamps  in  sections  when  not  needed. 

Placing  of  Switches. — One  item  of  considerable  importance  in 
large  installations  is  the  placing  of  switches  at  uniform  places; 
that  is,  if  located  on  columns,  the  switches  should  be  placed 


\      V        -f        +'        -f        -4-'       -4-'        ^ 

-  -f       -f       -f 

-f           -f" 

j  *    f    *    *    f    f    *H 

-  f       -f       -f 

f            f 

^                                                                                             V 

is.'     I     -.-•         1        *--• 

^--     1 

|     *       +'       f*       -f       +*       -f      ~*H 

n                 a                 B  —  3 

^.   aa.-.-^-.fcfl  —  ^_* 
-     -f           -f           +~ 
• 

4-       I" 

• 
1 

FIG.  135. — Typical  working  plan  for  wire  men. 

on  the  same  relative  side  of  each,  and  on  columns  located  on  the 
same  side  of  the  aisle.  A  fairly  safe  rule  is  to  control  the  lamps 
in  rows  or  groups  parallel  to  the  windows  or  skylights.  This 
will  be  evident  by  reference  to  Fig.  135,  where  the  switching  is 
indicated  by  numerals  adjacent  to  each  lamp.  Those  lamps 
away  from  the  windows  will  be  required  in  many  cases  when  the 
work  nearer  the  windows  is  still  sufficiently  illuminated  by 
daylight.  If  lamps  are  controlled  in  rows  perpendicular  to  the 
windows,  all  units  in  a  row  will  necessarily  be  on  at  one  time, 
when  often  only  a  portion  is  needed. 

The  Working  Drawing. — A  complete  self-contained  working 
drawing  of  the  proposed  arrangement  of  lamps  will  contribute 
to  the  ease  of  installing  a  lighting  system  throughout  a  factory. 
Such  a  drawing  should  be  intelligible  to  the  average  wireman. 
It  should  give  the  outline  of  the  floor  space  to  be  lighted  and 


272     ENGINEERING  OF  SHOPS  AND  FACTORIES 

should  designate  the  light  units  in  some  clear  and  distinctive 
form,  located  to  scale  as  in  Fig.  124,  a  typical  working  drawing 
that  has  been  found  to  give  satisfaction  in  its  details.  This 
drawing  gives  the  dimensions  of  the  floor  space,  distance  between 
lamps  and  the  distances  between  walls  and  lamps.  The  speci- 
fications should  contain  the  number  and  type  of  lamps,  the 
number  and  style  of  reflectors,  the*  number  and  type  of  shade 
holders,  and  the  mounting  height  of  socket  above  floor.  The 
method  of  switch  control  is  perhaps  most  easily  shown  on  the 
drawing  by  placing  the  same  numeral  adjacent 'to  all  lamps  to 
be  controlled  from  a  given  switch.  It  will  be  found  advanta- 
geous to  furnish  the  maintenance  and  wiring  departments  with 
blue  prints  of  such  a  drawing. 

Maintenance  Problems. — The  foremost  item  connected  with 
the  operation  of  a  factory  lighting  system  is  its  systematic 
maintenance.  To  furnish  the  best  results  a  lighting  system 
should  be  maintained  with  the  same  care  which  attended  its 
installation.  The  factors  which  go  to  make  up  the  maintenance 
include  renewals  of  incandescent  lamps  and  the  cleaning  of 
reflectors  and  shades. 

First  of  all,  if  the  factory  is  sufficiently  large  to  warrant  it, 
there  should  be  an  organized  maintenance  department  for  looking 
after  this  work.  This  department  should  possess  an  accurate 
record  of  every  lamp  in  the  factory  and  its  type.  Arrangements 
should  be  made  for  carrying  in  stock  a  sufficient  supply  of 
repair  parts  and  renewals.  It  is  important  that  a  record  be 
made  of  all  such  repairs  as  well  as  of  the  renewals,  together  with 
the  labor  involved.  These  records  will  show  the  maintenance 
cost  of  the  various  units  and  will  serve  to  indicate  if  this  expense 
is  excessive,  due  to  abnormal  conditions  in  the  circuits,  in  the 
handling  of  the  lamps  or  otherwise.  In  lamps  possessing  mech- 
anism repairs  are  necessary,  and  the  trimming  of  arc  lamps  is 
the  large  item  to  be  charged  to  a  system  in  which  they  are  used. 

The  designing  engineer  may  be  of  service  in  preventing  excess 
maintenance  by  seeing  that  the  lamps  are  so  located  that  the 
renewals  may  be  easily  made.  A  practical  instance  will  indicate 
how  the  maintenance  may  be  affected  by  the  method  of  installing 
the  lamps.  In  buildings  of  open  steel  construction,  so-called 
stringer  boards  are  often  placed  between  girders,  as  lamp  sup- 
ports. If  these  boards  are  not  of  sufficient  strength  to  support  a 
ladder,  renewals  and  cleaning  of  lamps  will  be  difficult.  The 


FACTORY  LIGHTING  273 

higher  expense  for  providing  boards  of  sufficient  size  will  be 
offset  by  the  greater  ease  in  making  renewals,  thus  reducing  the 
maintenance  expense. 

Cleaning  Reflectors. — The  cleaning  of  glass  reflectors  is  an 
important  item.  The  depreciation  of  the  efficiency  of  reflectors 
of  all  kinds  due  to  the  accumulation  of  dust  and  dirt  is  large. 
The  proper  time  to  clean  reflectors  is  when  the  value  of  the  light 
lost,  due  to  dust  and  dirt  accumulations,  equals  the  labor  and 
material  cost  of  cleaning  them. 

In  order  to  realize  the  best  results  from  such  a  maintenance 
department  it  is  desirable  that  all  lighting  installations  be  in- 
spected once  a  day.  An  inspector  making  his  rounds,  should 
report  all  lamps  out  of  service,  together  with  the  number  of 
lamps  missing  or  otherwise  in  need  of  repairs.  This  information 
embodied  in  a  report  and  furnished  to  the  maintenance  depart- 
ment in  such  form  that  all  defective  lamps  can  be  located  quickly, 
will  permit  of  promptly  replacing  such  lamps,  and  will  furnish 
at  the  same  time  a  valuable  record  for  calculating  the  mainte- 
nance costs. 

Cost  Comparisons. — Cost  figures  should  not  be  permitted  to 
stand  alone,  but  should  be  weighed  with  a  due  consideration  of 
the  usefulness  of  the  light  as  an  invaluable  accompaniment  of 
quality  and  quantity  of  work  produced  in  a  given  time.  If  the 
factory  manager  can  gain  something  of  this  attitude  to  the  light- 
ing question,  viewing  the  matter  as  an  asset  to  factory  produc- 
tion, and  will  study  the  kind  and  quality  of  light  most  suitable 
to  each  condition  of  work,  better  results  may  be  expected  than 
when  all  attention  is  fixed  on  slight  differences  in  first  cost  or 
annual  charges. 

Certain  illumination  data,  which  has  been  taken  from  actual 
installations  in  a  factory,  is  shown  in  Table  XXIII.  The  informa- 
tion contained  in  this  table  is  not  intended  to  serve  as  a  rule  for 
factory  work  in  general,  but  may  be  used  as  a  guide  in  other 
locations  where  the  ceiling  heights  correspond  and  where  sur- 
roundings are  comparable. 


is 


274     ENGINEERING  OF  SHOPS  AND  FACTORIES 


and  character  of 
undings2 

03                                                                                                             GO                           C 

?                           «                                        *      d                         ^                           C 

?         .               =^^.^^                    .       *     ,»          .       M 

^'^^2     .^os^^oj^^^^^^c 

9  "a  1  a  •«  ^  ^"^  *  -^  1  §  £  !  !  ' 

^'S^'^aOOlSO'^^^-'^^g 
o      ^^^^^^O^I^-^bJO^M 

a  g3  s  o  b£  bo  bio  c  bio  bc^  -a.s  -§  1  -a 

^s^  c^^^  sili*!  ^^-§ 

1  s  Sll-Hvlll  ||  1  11^ 

O     O   '"^   '^                          O                 ,t2   <--     0   "fll   •"   **^ 

qd 

1 

o 

a  J2  ^2 

X     O     O 

«  1  1 

M     bJO    bJD 

a 

'o 

g 

bO 

a 

*cu 
03 

If 

12  i  *S  '§  S  J  S  ^  J  J  1  *8  8*  o  8  1 

-S)^   §  ^    ,^^|  ^^  o   §  .§   a   o 

03   S   S 

CU 
CU 

1 

^  ^   c   S  ^  T  ^  T  ^  T      ^  ^  T  ^       ^  v  c  -b 

J»ifrfi^8*8l4f8ftrf-if.lft-4f4   ' 

QOO^f^^^O^^o°^^O§ 

^^^.Scu0cu^cucu^^bJDa^^ 

-^j2^  S  S  S  S^  2  SJ-^.S^rn  5  ^ 

^   M   -^ 

CU 
fl     bJD    bJO 

o 
(4 

O 

|fla^^^^a^rSJa^a>§o)^ 

cucucuo3o3o3o3cuo3c3cU'O'o3ag>)a>>. 

QWwSSSSm^SQwSEwK 

la 

03   '""   '"§ 

CU 

U 

T^    t~^*    CO    C^    CO    CO    f^O    00    ^O    ts»    CO    ^O    CO    00    !>•    00 

S  g.g 

1 

If 

CM    <M    CM 

c 

tSi 

cu    £ 

coOOOOOOOOOOOiOtOio»O 

000 

10  »c  10 

1 
*> 

ti~ 

o 

l- 
DH 
—1 

r^ 

aaaaaaaaaaaaaaaa 

.S  .S  .S 

o> 

$ 

£ 

ocooscoosoooocoosooooo 

000 

i) 

.Is 

OOOOOOOSOOOOOOOOOOOOOOCO(N^(N 

(M    C^    <M 

-5 

bO 

xxxxxxxxxxxxxxxx 

XXX 

a 

a 

aaaaaaaaaaaaaaaa 

a   a   a 

£ 

| 

oooooooooooocoooo 

000 

o 

CO 

^j^j^j^j^j^j^j^j^j^j^j^j^^jjj^ 

bl_t*HVh-l<4-|<4-l«4-H<+-l%-l<4-|(4-<<^>+H%-H<4^«4-|Cl-l 

000000000000t>»ts»00000000'—  'OCOO 

43  43  43 

000 

1 

*o3 

bJD    > 

aaaaaaaaaaaaaaaa 

a   a   a 

•2  -o  n 

COCOCOOOCOCOCOOOCO(M(N(N(MCO 

l-H 

CO    CO    t>- 

c 

if   "o  B9 

^J       +J       -^       ^J       ,^J       ^      _jj      _+j      >+J        ^J      ^        ^J        ^J        4_'        ^J       +J 

43  d3  43 

• 

S  -^ 

§ 

^ 

i-H     <M 

<N    CM    <N 

5 

^ 

| 

O      Wl 

aaaaaaaaaaaaaaaa 

a   a   a 

J5?  ,a 

r-HO—  IOSOSOOOCOOOOOOOOOS 

OS   OS   (N 

CU 

^J^^J^J^J^J^J^J^J^J^J^J^J^J^i^J 

«4^t4-,<«-l<4-l«4-l«4-|t4-|t4-|t«-l<4-l<4-(C4_,C+_l(+HC+Ht4_, 

OOOSrH^-ii—  ICM(NCM(NCOCOCOCOCOCOT^ 

43  43  43 

" 

•£b 

FACTORY  LIGHTING  275 

A  TYPICAL  FACTORY  LIGHTING  PROBLEM 

As  a  typical  example  of  factory  lighting  in  which  many  appli- 
cations of  the  principles  previously  stated  are  in  evidence,  a 
factory  building  will  be  considered  which  contains  more  than 
225,000  sq.  ft.  of  floor  space  and  in  which  over  3000  tungsten 
lamps  have  recently  been  installed.  This  building,  a  plan  of 
which  is  shown  in  Fig.  136,  consists  of  eight  floors,  mostly  devoted 
to  the  manufacture  of  small  machine  parts.  The  walls  are 
light  in  color  and  the  building  has  the  advantage  of  a  light  ceil- 
ing. The  height  from  floor  to  ceiling  is  13  ft.  6  in.  and  the  build- 


.  ..  x  x  x  :.ft:  x xxx x ,.... ............ ,.,.,.,.. 

: : :  r^~b' : : :  : : : :  n^w : 


FIG.  136. — Arrangement  of  lamps.  f  One  floor  of  factory  building. 

ing  is  divided  into  bays  of  16  by  70  ft.  The  work  may  be  classi- 
fied into  bench  work,  requiring  in  many  cases  good  illumination 
on  vertical  surfaces;  machining  work,  where  line  shafting  and 
belting  form  an  obstruction  to  the  light;  assembly  work,  often 
performed  on  the  floor  where  illumination  on  the  horizontal, 
inclined  and  vertical  surfaces  is  imperative;  and  a  storage  ware- 
house, where  low  intensity  is  sufficient. 

The  ceilings  are  of  wood  and  hence  wooden  moulding  was 
advantageously  used.  Switches  were  placed  on  central  col- 
umns, on  the  same  side  of  the  aisle  throughout  and  on  the 
same  relative  side  of  each  column  wherever  possible.  In  feed- 
ing the  switches,  iron  conduit  was  run  down  the  cement  columns, 
and  iron  outlet  boxes  served  the  double  purpose  of  supports  for 
the  snap  switches  and  of  wall  receptacles  as  outlets  for  extension 
lines  when  required. 

Lighting  Requirements. — The  requirements  for  the  lighting 
in  this  building  may  be  enumerated  as  follows: 

1.  Sufficient  general  illumination  for  all  ordinary  purposes. 

2.  Intensities  of  illumination  higher  in  some  locations  than 

others. 

3.  Higher  intensities  predominating  on  horizontal  surfaces  in 

certain  sections. 


276     ENGINEERING  OF  SHOPS  AND  FACTORIES 

• 

4.  Sufficiently  high  intensities  on  vertical  surfaces. 

5.  Glare  reduced  to  minimum. 

One  of  the  very  trying  conditions  was  that  of  providing  suffi- 
cient illumination  for  the  classes  of  work  where  varied  inten- 
sities were  necessary,  and  at  the  same  time  maintain  a  uniformity 
of  installation  and  distribution  of  illumination,  so  that  work 
could  be  done  with  equal  ease  at  Sny  portion  of  the  floor  space. 
This  feature  was  taken  care  of  by  providing  outlets  with  standard 
spacings  all  over  the  building  except  in  the  warehouse  and 
storerooms,  and  by  varying  the  intensity  where"  necessary  by  a 
change  in  the  size  of  the  lamps.  It  will  be  seen  that  this  is  an 
excellent  feature  of  a  distributed  system  of  lighting,  since  a 
change  in  the  size  of  the  lamps  and  reflectors  in  no  way  changes 
the  uniformity  or  the  distribution  characteristics  of  the  result- 
ing illumination. 

Experiments  and  Steps  Leading  to  Final  Arrangement. — As  a 
first  step  several  bays  on  one  of  the  floors  were  equipped  with 
100-watt  tungsten  lamps  spaced  8  ft.  apart  'and  2  ft.  6  in.  from 
walls,  the  lamps  being  mounted  at  the  ceiling.  This  size  of 
lamp  seemed  best  adapted  to  the  ceiling  height,  and  the  size  of 
bay  was  not  only  very  suitable  for  this  spacing  (since  eighteen 
lamps  filled  one  bay)  but  the  arrangement  was  symmetrical 
with  respect  to  the  bay  itself.  The  ratio  of  spacing  distance  to 
mounting  height  called  for  concentrating  reflectors,  which  were 
installed  along  with  bowl-frosted  lamps.  Several  adjoining  bays 
were  equipped  with  lamps  of  the  same  size  but  with  different 
types  of  reflectors,  both  glass  and  metal.  These  trial  bays  were 
left  in  service  for  several  months  so  that  the  opinions  of  all  con- 
cerned, including  the  workmen,  could  be  obtained,  and  also  for 
the  purpose  of  making  tests  and  noting  the  effect  of  dust  and 
dirt  on  each  type  of  reflector.  Six  lamps  were  controlled  per 
switch,  thus  requiring  three  switches  per  bay,  all  three  switches 
being  mounted  on  one  column.  A  trial  was  also  made  of  several 
bays  with  bare  lamps  to  note  whether  the  resulting  illumination 
was  noticeably  less  than  that  with  reflectors.  It  was  thought 
that  the  shielding  effect  of  the  girders  might  serve  as  a  suffi- 
cient protection  for  the  eyes  of  the  workmen  without  the  addi- 
tion of  shades  or  reflectors.  Furthermore,  various  mounting 
heights  and  various  shapes  of  reflectors  were  tried  for  the  pur- 
pose of  investigating  the  proportionate  relation  of  downward 
and  side  light.  The  same  procedure  was  also  tried  with  other 


FACTORY  LIGHTING  277 

sizes  of  lamps  and  reflectors  so  as  to  determine  whether  the  size 
nominally  selected  was  most  suitable  for  the  purpose. 

Notes  on  Final  Arrangement. — The  main  results  from  these 
experiments,  covering  several  months,  were  as  follows: 

1.  Size    of   Lamps. — The    100-watt   lamps   seemed   the   best 
average  size,  but  at  least  two  intensities  were  found  advisable, 
one  somewhat  high  for  detail  and  machine  work,  and  a  lower 
intensity  for  assembly  work. 

2.  Mounting  Height. — Of  the  various  mounting  heights  tried, 
it  was  found  very  desirable  to  mount  the  lamps  as  close  to  the 
ceiling  as  possible,  so  that  glare  was  reduced  to  a  minimum. 

3.  Number  of  Lamps  per  Bay. — The  general  scheme  of  instal- 
ling eighteen  lamps  per  bay  seemed  best. 

4.  Arrangement  of  Switches. — The  switching  of  six  lamps  per 
circuit,  while  possessing  some  good  features,  did  not  seem  a 
sufficient  sub-division.     At  times,   the  work  directly  next  to 
windows  was  sufficiently  lighted  by  daylight,  while  the  work 
under  the  second  row  of  lamps  was  not.     This  led  to  the  conclu- 
sion that  the  lamps  next  to  the  windows  in  each  bay  should  be 
on  one  switch,  and  four  lamps  per  switch  in  general  seemed  a 
better  arrangement  than  six. 

5.  Depreciation   Due  to   Dust. — It   was  found   after   several 
months  of  service,  during  which  time  the  reflectors  were  allowed 
to  remain  uncleaned,  that  tests  on  each  of  the  reflectors  before 
and  after  cleaning  indicated  about  the  same  degree  of  reduction 
in  efficiency.     It  was  noted,  however,  that  reflectors  located 
near  belting  became  covered  with  dirt  in  very  much  less  time 
than  when  the  lamps  were  in  a  clear  open  space. 

6.  Intensity  of  Illumination  on  Other  than  Horizontal  Surfaces. 
— While  the  ratio  of  spacing  distance  to  mounting  height  of  the 
lamps  called  for  a  concentrating  reflector  for  producing  uniform 
downward  light,  a  distributing  reflector  was  essential  to  provide 
side  light.     An  intensity  of  about  two  foot-candles  on  the  sides 
of  machines  seemed  to  be  sufficient.     For  reasons  previously 
stated,  in  certain  portions  of  the  building  the  reduced  intensities 
of  the  illumination  on  the  horizontal  surfaces,  owing  to  distribut- 
ing reflectors  being  used,  which  directed  a  larger  proportion  of 
the  light  upon  the  vertical  surfaces,  was  made  up  by  the  use  of 
higher  candle-power  lamps  than  originally  contemplated. 

7.  Bowl-frosted    versus    Clear    Lamps. — Bowl-frosted    lamps 
proved  not  so  desirable  as  clear  lamps,  due  to  the  more  rapid 


278     ENGINEERING  OF  SHOPS  AND  FACTORIES 

effect  of  dust  and  dirt  on  the  frosting.     This  effect  is,  of  course, 
particularly  noticeable  in  factory  work. 

8.  Metal  versus  Glass  Reflectors. — Metal  reflectors  in  these 
locations  were  far  inferior  to  glass  because  no  light  passes  through 
them.     Glass  reflectors,  on  the  other  hand,  permit  some  of  the 
light  to  pass  through  the  reflector^,  which  in  turn  is  reflected 
from  the  light  ceiling  and  walls. 

9.  Advantages  of  Reflectors. — Lamps  without  reflectors  were 
debarred  on  account  of  the  glare  which  resulted  when  a  man 
looked  up  from  his  work  and  further,  since  62  per  cent,  more 
illumination  was  delivered,  on  the  working  surfaces  by  lamps 
equipped  with  reflectors  than  with  bare  lamps  of  the  same  size. 
It  was  considered  a  good  investment  from  these  two  important 
standpoints,  to  provide  all  lamps  with  the  most  efficient  reflec- 
tors available,  conclusive  tests  showing  very  clearly  that  cheap 
ones  rarely  justify  their  cost. 

Some  Comments  on  This  System. — This  tungsten  lighting  sys- 
tem has  now  been  in  service  long  enough  to  indicate  that  for  a 
majority  of  the  work  in  this  building,  the  illumination  facilities 
are  unusually  satisfactory.  Experts  have  viewed  this  lighting 
arrangement  and  have  expressed  the  opinion  that  this  particu- 
lar factory  is  one  of  the  best  lighted  buildings  in  the  country, 
bringing  out  many  valuable  points  in  recent  illuminating  engineer- 
ing practice.  A  great  many  individual  lamps  were  used  previous 
to  the  new  lighting  system,  and  it  was  thought  by  workers  and 
foremen  that  these  lamps  would  have  to  be  left  in  service  not- 
withstanding the  new  overhead  lighting  installation;  practically 
all  individual  lamps  were  taken  out,  however,  with  the  under- 
standing that  they  would  be  put  back  after  several  weeks  if 
found  necessary.  The  object  has  been  to  give  a  sufficiency  of 
light  to  every  workman,  and  it  was  found  that  a  very  much  less 
number  of  individual  lamps  were  called  for  than  were  formerly 
thought  to  be  necessary.  Here  and  there  a  drop  lamp  has  been 
installed  to  take  care  of  some  special  work  requiring  light  at  an 
unusual  angle  or  of  more  than  ordinary  intensity;  but  as  an 
evidence  of  the  acceptability  of  the  new  light,  it  may  be  stated 
that  during  the  past  winter  since  the  new  system  has  been 
installed,  the  complaints  and  calls  for  changes  in  the  wiring  have 
been  negligible,  compared  to  the  extreme  number  of  similar  com- 
plaints during  the  preceding  winter  when  a  system  of  inferior 


FACTORY  LIGHTING 


279 


FIG.  137. — Shop  interior  lighting. 


FIG,  138, — Shop  interior,  well  lighted, 


280     ENGINEERING  OF  SHOPS  AND  FACTORIES 

lighting  was  in  service.     This  fact  in  itself  is  an  unquestionable 
recommendation  of  the  new  lighting  system. 

One  point  of  interest  in  connection  with  this  lighting  installa- 
tion is  that  the  final  arrangement  was  the  outcome  of  experience 
rather  than  predetermination.  Months  of  careful  investigation 
and  trial  were  made  of  the  various  schemes  as  indicated  in  the 
preceding  notes,  and  the  completed  work  was  chosen,  on  a 
basis  not  only  of  these  tests,  but  also  on  the  opinions  of  those 
who  were  to  work  under  the  lighting.  Theory  and  formula  give 
a  general  basis,  but  often  fail  to  take  account  of"  certain  prac- 
tical conditions.  For  example,  the  reflection  from  ceilings  and 
walls;  the  color  of  machinery  or  materials;  the  need  for  numerous 
lamps  of  smaller  size  to  prevent  shadows  which  are  unavoidable 
with  high  candle  power  units,  and  the  allowance  to  be  made  for 
dust  and  dirt  on  lamps  and  reflectors,  are  points  which  show 
why  .many  things  must  be  considered,  aside  from  the  mere  area 
to  be  lighted,  if  satisfactory  results  are  to  be  assured. 


CHAPTER  XXIII 
DRAINAGE  OF  INDUSTRIAL  WORKS1 

The  drainage  of  industrial  plants  may  include  not  only  the 
drainage  of  the  individual  buildings,  but  the  arranging  and 
laying  of  a  complete  system  of  sewers,  the  importance  of  the 
latter  being  proportionate  to  the  whole  undertaking.  As  so 
many  manufacturers  are  now  erecting  new  works  on  suburban 
or  rural  sites,  where  abundant  opportunity  exists  for  expansion, 
the  importance  of  drainage  is  increased.  In  such  cases,  the 
laying  out  of  a  sewerage  system  differs  but  little  from  that  for  a 
small  town  or  village,  and  this  condition  is  assumed  in  the  fol- 
lowing pages. 

The  science  of  sanitary  engineering  is  of  late  origin,  for  not 
until  the  middle  of  the  nineteenth  century  did  the  people  fully 
realize  that  their  lives  were,  to  a  great  extent,  in  their  own  hands, 
and  that  many,  if  not  the  majority  of  deaths  might  be  avoided. 
The  application  of  sanitary  drainage  to  manufacturing  plants  is 
still  more  recent,  for  most  of  the  old  style  factories  had  only  the 
crudest  accommodations  in  this  respect. 

In  this  connection ' one  writer  says,  "If  the  air  is  vitiated, 
water  rendered  impure,  or  food  improper  or  insufficient,  the 
body  is  robbed  of  life-giving  elements  and  soon  succumbs  to 
disease  and  death.  It  is  the  true  aim  of  the  sanitary  engineer 
to  assist  nature  in  her  great  but  simple  operations,  to  facilitate 
the  purification  of  air,  to  prevent  dangerous  impurities  entering 
our  supplies  of  water,  to  furnish  an  abundance  of  these  life-giving 
elements,  and  to  remove  as  speedily  as  possible  before  decomposi- 
tion commences  all  those  matters  eliminated  from  animal 
bodies,  together  with  all  decomposing  refuse/' 

The  study  of  sanitary  drainage  is  essentially  one  of  life, 
for  health  and  longevity  are  natural,  while  disease  is  abnormal, 
death,  except  from  old  age,  is  accidental,  and  both  are  to  a  large 
extent  preventable  by  human  agencies.  But  no  sooner  do 
human  beings  begin  to  live  and  work  in  one  place,  than  danger 

1  H.  G.  Tyrrell,  in  Municipal  Journal  and  Engineer,  May,  1901. 

281 


282     ENGINEERING  OF  SHOPS  AND  FACTORIES 

from  decomposing  refuse  begins.  As  hamlets  increase  to  villages, 
and  these  again  to  towns  and  cities  with  the  many  and  crowded 
workshops,  the  danger  becomes  greater.  Hence  from  the  first 
it  is  important  that  the  greatest  attention  should  be  given  to 
the  drainage  of  the  place. 

During  twenty-two  years  of  continuous  war  on  the  continent, 
England  sustained  a  loss  of  79,0<5b  men,  but  in  one  year  of 
cholera  her  loss  was  144,000.  In  the  British  army  before  sani- 
tary improvements  had  been  installed,  the  death  rate  was  one  in 
forty-two,  with  two  sick  men  out  of  every  five  picked  and  able- 
bodied  men.  But  after  a  more  perfect  system  had  been  pro- 
vided, the  death  rate  was  only  one  in  one  hundred  and  forty- 
three,  with  one  sick  out  of  every  twenty-one.  Epidemics  of 
disease  are  too  often  ascribed  to  "  an  act  of  Providence  to  whose 
ruling  all  must  submit,  but  looking  with  the  eyes  of  science 
upon  the  overflowing  cesspools  and  reeking  sewers  as  inevitable 
causes,  and  with  the  eye  of  humanity  upon  the  interested  and 
innocent  victims  languishing  in  pain  and  peril,  or  mouldering 
in  their  shrouds,  such  implications  of  Providence,  though  per- 
haps sincerely  made,  are  next  to  blasphemy,  especially  when 
uttered  by  the  agents  who  are  responsible,  though  the  prayer  of 
charity  might  be,  "Father  forgive  them  for  they  know  not 
what  they  do." 

The  Drainage  of  Buildings. — The  final  object  of  any  system 
of  sewers  however  elaborate  or  complicated,  is  the  drainage  of 
buildings.  In  order  that  this  drainage  may  be  complete,  the 
following  requirements  should  be  kept  in  view: 

1.  The  foundation  soil  shall  be  free  from  dampness. 

2.  All   liquid    and   excremental    waste   shall   be   safely    and 
quickly  conveyed  beyond  the  building  limits. 

3.  A  constant  supply  of  pure  air  shall  be  admitted. 

4.  Nothing  shall  be  allowed  to  collect  about  the  place  which 
would  taint  the  air  or  render  the  atmosphere  impure. 

5.  Proper  arrangement  must  be  made  to  prevent  the  entrance 
of  sewer  gas  through  traps  or  other  fixtures. 

The  first  of  these  requirements,  that  the  subsoil  be  free  from 
moisture,  is  of  great  importance.  If  a  basement  or  cellar  is 
always  damp,  and  gases  are  continuously  rising  through  the  shop?, 
it  is  impossible  that  the  occupants  be  hale  and  strong.  If  the 
foundation  is  of  gravel  or  sand,  no  other  drainage  is  necessary. 
But  where  clay  occurs,  as  is  usually  the  case,  a  2-in.  drain  all 


DRAINAGE  OF  INDUSTRIAL  WORKS  283 

around  just  inside  the  wall  and  about  a  foot  or  so  from  it,  will 
be  needed.  Similar  ones  should  be  placed  at  distances  apart  of 
about  15  ft.,  crosswise  of  the  building.  To  prevent  the  exhala- 
tion of  moisture  which  rises  even  the  driest  soil,  a  coat  of  some 
impervious  substance  such  as  dense  concrete,  asphalt  or  hydrau- 
lic cement  should  be  spread. 

Perhaps  the  most  difficult  of  all  in  this  connection  is  the 
arranging  of  pipes  and  fixtures  for  the  removal  of  waste.  If  the 
pipes  are  of  lead  their  durability  will  be  much  increased  by 
giving  them  a  thick  coat  of  paint  inside,  and  when  thus  protected 
and  well  ventilated,  they  should  last  from  twenty  to  thirty  years. 
Iron  pipes  are  sometimes  used  and  they  are  usually  screwed 
together,  thus  being  strong  enough  to  support  their  own  weight 
with  the  help  of  straps.  Around  the  joints  spherical  covers  are 
sometimes  placed,  so  that  a  slight  settling  of  the  pipes  will  not 
break  the  connection. 

The  essential  features  in  the  arrangement  of  waterclosets, 
sinks,  etc,  are: 

1.  Extension  of  all  soil  and  waste  pipes  through,  and  above 
the  roof. 

2.  Provision  of  fresh-air  inlet  in  the  drain,  at  the  foot  of  the 
soil-  and  waste-pipe  system. 

3.  Trapping  of  the  main  drain  outside  of  the  fresh-air  inlet. 

4.  Placing  of  each  fixture  as  near  as  possible  to  it,  with  a 
self-cleansing    trap,    safe    against    siphonage    and    back 
pressure. 

5.  Locating  of  vent  pipes  to  traps  under  such  fixtures  as  are 
liable  to  be  emptied  by  siphonage. 

Thus  by  having  a  ventilation  at  both  ends  of  the  soil  pipe, 
the  accumulation  of  foul  gases  is  prevented,  which  would  very 
soon  destroy  lead  pipe.  Without  this  ventilation,  traps  are 
always  liable  to  be  forced  or  siphoned,  owing  to  the  force  of 
tides  or  winds  at  the  mouth  of  sewers,  or  to  a  change  of 
temperature. 

While  the  fresh-air  inlet  at  the  foot  of  the  soil  pipe  is  benefi- 
cial as  a  ventilator,  it  is  obnoxious  on  account  of  emitting  gas. 
Waste  pipes  from  sinks  should  have  traps  outside  the  building 
near  the  wall,  to  catch  oily  matter  before  it  hardens.  Catch 
basins  may  be  made  of  brick  or  concrete  about  4  ft.  in  diameter, 
with  pipes  arranged  to  siphon  when  the  chamber  is  full.  If  the 
catching  of  grease  is  not  the  object,  a  flush  tank  may  be  substi- 


284     ENGINEERING  OF  SHOPS  AND  FACTORIES 


tuted.  When  the  tank  is  full,  one  more  flow  of  water  into  it 
starts  the  siphon  acting  which  empties  it  nearly  to  the  bottom. 
In  some  cases,  slops  may  be  disposed  of  by  carrying  them 


FIG.  139. — SiphoiTtank. 

through  a  system  of  pipes  with  open  joints,  laid  underneath 
some  adjoining  farm  land  or  meadow.  Before  entering  the 
open  drains,  the  water  passes  through  a  flush  tank,  making  the 


FIG.  140. — Line  of  wash  bowls. 

discharge  intermittent,  and  the  flow  of  water  being  more  copious, 
saturates  the  ground  to  a  greater  distance. 

Waterclosets  are  the  most  troublesome  of  all  plumbing  ar- 
rangements.    It  would  be  well  if  they  were  built  separate  al- 


DRAINAGE  OF  INDUSTRIAL  WORKS  285 

together  from  the  main  buildings,  but  as  this  would  to  a  great 
extent  destroy  their  convenience,  they  may  be  separated  from 
the  shop  by  a  ventilated  lobby  or  by  double  doors,  and  they 
should  always  have  outside  windows.  The  most  approved  ar- 
rangement is  to  place  all  toilets  in  a  single  room  on  each  story,  or 
to  group  them  all  in  one  story,  usually  the  basement  or  the  upper 
floor.  Fixtures  should  be  extra  heavy  as  they  often  get  rough 
usage.  Enough  wash  bowls  (Fig.  140)  should  be  provided  so 
there  will  be  at  least  one  for  every  three  people  in  the  building, 
and  not  less  than  one  toilet  for  every  twelve  persons.  Enameled 
iron  ware  is  so  much  cleaner  than  any  other,  that  it  should  in- 


FIG.  141. — Cluster  of  showers. 

variably  be  used,  and  wood  excluded.  Foundries  are  especially 
in  need  of  efficient  wash  rooms,  and  in  some  cases,  one  bath 
room  is  provided  for  each  workman.  In  some  states,  the  law 
requires  that  foundries  shall  have  shower  baths  (Fig.  141)  and  full 
provision  for  the  comfort  and  cleanliness  of  operatives.  These 
rooms  should  be  in  charge  of  an  attendant  whose  duty  it  is  to 
keep  them  clean.  The  walls  and  floors  should  be  of  cement  or 
tile,  so  a  hose  can  be  used  for  washing.  A  room  for  the  storage 
of  clothing  should  adjoin  the  wash  room,  and  this  should  have 
individual  lockers  with  perforated  sides  for  ventilation,  metal 
ones  being  preferred. 

Watercloset  fixtures  (Fig.  142)  are  made  in  great  variety,  and 


286     ENGINEERING  OF  SHOPS  AND  FACTORIES 


most  of  the  large  manufacturers  will  forward  their  catalogues  to 
prospective  buyers  on  request.  Many  fixtures  are  made  espe- 
cially for  factory  use.,  and  as  a  descrip- 
tion of  them  would  fill  a  whole  book,  it 
is  impossible  to  even  mention  the  good 
points  which  are  obtainable.  They  m/^  '\ 
should  have  a  tight  valve  and  a  double 
water  seal,  with  water  enough  under 
the  seat  for  immediate  disinfection. 
Many  sanitary  authorities  prefer  the 
simple  hopper  closet,  since  its  only  trap  Tank  31 7 

is  always  in  sight.  Where  an  inter- 
mittent water  supply  of  about  fifteen 
minutes  is  provided,  it  is  perhaps  the 
best.  Two  types  of  urinals  are  shown 
in  Figs  143  and  144. 


A,  inlet 

B,  outlet 

C,  seat 

D,  valve 

E,  tank 


FIG.  142.— Water-closet. 

F,  auxiliary  «/,     check-valve 

valve 

G,  inner  cham-  L,    bowl 

ber 
H,  float  M,    bowl  outlet 


The  Drainage  of  Plants. — When  building  new  plants  in  rural 
or  suburban  places,  it  is  often  necessary  to  design  a  sewerage 


DRAINAGE  OF  INDUSTRIAL  WORKS 


287 


system  extensive  enough  to  include  not  only  the  plant  itself, 
but  the  whole  industrial  village,  and  for  this  reason  a  discussion 
is  given  of  the  drainage  of  the  yards  and  entire  site. 

Sewers  were  originally  for  surface  drainage  only,  and  it  was 
then  unlawful  to  discharge  refuse  or  foul  matter  into  them.  But 
in  1847,  this  idea  seems  to  have  been  reversed,  as  an  act  of 
Parliament  made  it  compulsory  for  all  drainage  in  cities  and 
towns  in  England  to  be  discharged  into  the  public  sewers.  They 


FIG.  143. — Trough  urinals. 


must  be  of  the  proper  size  with  sufficient  fall,  and  means  should 
be  provided  for  flushing  them.  A  system  of  sewers  should  be 
perfectly  tight  from  end  to  end,  for  if  they  allow  foul  liquids 
and  gases  to  permeate  the  ground,  they  are  no  better  than 
vaults  or  cesspools. 

In  starting  to  lay  out  a  system  of  sewers  for  a  manufacturing 
plant  or  industrial  village,  even  though  it  is  not  intended  to 
complete  the  whole  of  it  at  first,  a  plan  should  be  made  showing 
the  final  creation,  so  that  when  it  is  ended,  the  arrangement 
will  be  in  accordance  with  the  original  design. 


288     ENGINEERING  OF  SHOPS  AND  FACTORIES 

The  fall  or  inclination  of  sewers  is  important,  and  the  following 
table  gives  the  proper  grades  for  those  running  either  full  or 
half  full. 


FIG.  144. — Plan  of  separate  urinals. 


6-in.  pipes. 
9-in.  pipes. 
12-in.  pipes. 
15-in.  pipes. 
18-in.  pipes. 
24-in.  pipes. 
30-in.  pipes. 
36-in.  pipes. 
48-in.  pipes. 

Grade  1  in    60  j 
Grade  1  in    90 
Grade  1  in  200 
Grade  1  in  250 
Grade  1  in  300 
Grade  1  in  400] 
Grade  1  in  500 
Grade  1  in  700 
Grade  1  in  800 

DRAINAGE  OF  INDUSTRIAL  WORKS  289 

When  the  direction  changes,  the  friction  increases  and  the  fall 
must  be  greater.  The  most  rapid  fall  should  be  given  at  the 
upper  end  of  the  sewer  where  the  quantity  of  water  is  least  and 
consequently  where  the  velocity  is  needed  to  start  the  flow. 
Instances  are  known  in  which  inaccuracies  of  1/16  to  1/8  in. 
in  the  grade  of  sewers  rendered  them  inefficient  and  necessitated 
their  removal,  but  in  such  cases  the  inclination  was  very  small, 
not  exceeding  7  or  8  in.  per  mile. 

If  the  amount  of  water  flowing  is  proportional  to  the  size  of 
the  conduit,  sewers  of  different  sizes  give  the  same  velocity  at 
different  inclinations.  For  example,  a  10-ft.  sewer  with  a  fall 
of  2  ft.  per  mile;  a  5-ft.  with  a  fall  of  4  ft.  per  mile;  a  2-ft.  with  a 
fall  of  10  ft.  per  mile;  and  a  1-ft.  with  a  fall  of  20  ft.  per  mile, 
will  all  have  the  same  velocity,  but  the  10-ft.  sewer  will  require 
100  times  as  much  sewage  as  will  the  1-ft.  sewer  and  unless  it 
carries  a  volume  of  water  proportional  to  its  capacity,  the 
velocity  of  its  stream  will  be  correspondingly  lessened.  It 
becomes,  therefore,  especially  important  that  the  size  of  the 
conduit  be  adjusted  to  the  volume  of  the  stream.  When  half 
full  and  when  full,  the  velocity  is  the  same,  and  when  a  little 
more  than  three-quarters  full  the  velocity  is  greatest. 

In  determining  the  size  of  a  sewer  it  is  necessary  to  consider 
not  only  its  fall,  but  also  the  amount  of  rainfall  and  sewage 
which  it  must  carry  away.  The  commonest  of  all  defects  is 
thai  expensive  one  of  being  too  large.  It  is  much  better  to  have 
occasional  repair  after  excessive  rainfalls,  than  to  provide  for 
extraordinary  ones.  The  invariable  result  of  making  a  sewer 
too  large  is  that  sediment  forms  in  the  bottom  and  before  long 
it  is  clogged  with  filth,  or  only  a  small  orifice  remains  large 
enough  for  the  ordinary  flow.  Whereas,  had  the  sewer  been  of 
proper  size  at  first,  it  would  by  its  own  flow,  have  been  kept 
clean,  and  would  have  received  a  much  greater  rainfall  than  the 
larger  but  choked  sewer. 

In  small  towns  and  villages  it  is  not  usual  to  allow  for  a  greater 
precipitation  than  J  in.  per  hour,  but  in  cities  where  the  area 
is  mostly  built  over,  and  water  can  more  easily  find  its  way  to 
the  sewers,  a  fall  of  J  in.  per  hour  is  allowed.  Even  in  popu- 
lous towns  and  cities  a  considerable  quantity  of  water  will  not 
reach  the  sewer  but  will  soak  into  the  ground  or  evaporate. 
Assuming  that  a  fall  of  J  in.  per  hour  reaches  the  sewer,  this 

19 


290     ENGINEERING  OF  SHOPS  AND  FACTORIES 

is  providing  for  a  much  heavier  fall,  probably  a  total  of  about 
1  in.,  the  average  amount  of  sewage  in  a  town  with  water  supply 
is  about  25  gallons  for  each  person  per  day,  half  of  which  will 
be  discharged  between  9  A.  M.  and  5  P.  M. 

As  a  stream  flows  on,  its  velocity  will  increase,  and  conse- 
quently its  volume  will  diminish.  ..*  Therefore,  a  pipe  running  full 
at  its  upper  end,  may  receive  a  large  quantity  more  during  its 
course.  A  street  in  London  has  a  brick  sewer  5J  ft.  high  and 
3|  ft.  wide  with  a  12-in.  pipe  laid  along  the  Bottom  for  a  dis- 
tance of  560  ft.  This  was  never  known  to  be  choked,  and  during 
storms,  stones  could  be  heard  rolling  along  the  bottom.  This 
pipe  is  rarely  more  than  half  full  at  the  head.  The  cross-sectional 
area  of  all  the  drains  entering  it  is  equal  to  that  of  a  pipe  30  ft. 
in  diameter.  Although  the  12-in.  pipe  is  always  clean,  the 
large  brick  sewer  is  constantly  collecting  deposits  of  filth,  20  or 
30  ft.  from  where  the  small  one  joins  it,  which  deposit  must  be 
removed  by  expensive  hand  labor.  Instances  have  frequently 
occurred  where  workmen,  by  mistake,  .have  put  in  pipe  as  sewers, 
which  the  architect  intended  for  a  single  building,  and  the  re- 
sult has  been  that  they  were  always  clean  and  served  their  pur- 
pose well. 

The  round  sewer,  as  a  general  rule,  is  the  best.  With  it, 
good  joints  can  always  be  made  by  turning  the  best  fitting  parts 
to  the  bottom,  and  they  have  the  greatest  area  for  their  perim- 
eter. The  pipes  should  always  be  hard  and  smooth,  for  if 
at  all  porous,  they  contaminate  the  adjoining  ground,  and  are 
more  subject  to  frost,  and  to  the  destroying  action  of  sewer  gases. 
If  there  is  danger  from  roots  of  trees,  it  is  advisable  to  lay  the 
pipe  in  cement.  Where  the  supply  of  sewage  is  very  intermit- 
tent, an  egg-shaped  sewer  is  sometimes  preferred,  because 
when  the  stream  becomes  very  shallow,  it  is  also  narrow,  so  that 
sediment  is  not  likely  to  collect.  This  shape  of  sewer  is  usually 
made  of  brick,  and  is  more  expensive  than  pipe. 

Ventilation  of  Sewers. — One  writer  described  the  danger  of 
unventilated  sewers  as  being  greater  than  that  of  a  steam  engine 
without  a  safety  valve,  for  while  in  the  latter  case,  the  lives  of 
only  a  few  are  exposed,  in  the  former,  the  health  and  life  of  the 
whole  community  is  at  stake.  As  temperature  changes,  tides 
rise  and  fall,  or  the  force  of  the  wind  at  the  mouth  of  the  sewer 
varies,  the  pressure  of  the  confined  gases  is  also  changed,  and 
since  the  amount  of  water  in  ordinary  traps  is  small,  they  will 


DRAINAGE  OF  INDUSTRIAL  WORKS  291 

probably  be  forced  or  siphoned.  If  siphoned,  a  direct  communi- 
cation for  the  entrance  of  poisonous  gases  will  be  established 
between  the  public  sewer  and  the  building.  Besides,  if  means  be 
provided  for  a  free  passage  of  air  through  the  sewer;  the  same 
amount  of  gas  will  not  be  generated,  for  much  of  the  foul  matter 
in  a  short  time  becomes  oxidized. 

Ventilation  by  means  of  water  pipes  to  the  eaves  of  build- 
ings has  been  advocated,  but  this  method  is  faulty,  in  that  dur- 
ing heavy  rains  when  most  needed,  the  pipes  are  choked  with  a 
flow  of  water.  Most  authorities  on  sanitation  have  decided  that 
the  best  sewer  ventilators  yet  used,  are  manholes  covered  with 
iron  gratings,  emerging  in  the  center  of  the  street.  The  char- 
coal ventilator  has  also  been  used  with  success,  for  in  a  city  of 
England  where  more  than  500  of  these  ventilators  were  installed, 
the  total  yearly  expense  was  less  $1.25  for  each.  The  arrange- 
ment consists  of  a  special  tray  covered  with  charcoal  set  in  the 
ventilator  so  that  all  gases  ascending  are  forced  to  pass  either 
through  or  over  the  charcoal.  When  it  is  remembered  that  1 
in.  of  charcoal  contains  as  much  interior  surface  as  100  sq.  ft., 
an  idea  can  be  formed  of  its  power  as  a  disinfectant.  Around 
the  special  tray  is  a  box  for  catching  any  rainfall  or  dust  which 
may  find  its  way  through  the  iron  grating.  These  ventilators 
in  order  to  give  thorough  satisfaction,  should  be  placed  every 
200  or  300  yd.  apart  in  the  sewer.  They  should  not  branch  off 
directly  from  the  sewer,  but  should  rise  from  a  camber  of  about 
a  foot,  so  that  passing  gases  will  be  lead  to  the  outlet.  When  the 
street  incline  is  great,  a  light  .hanging  valve  may  be  placed  above 
each  ventilator.  This  will  not  obstruct  the  flow  of  sewage,  but 
it  will  prevent  gases  rising  to  the  higher  part  of  the  system,  and 
escaping  all  from  one  place  or  through  a  few  ventilators. 

In  the  city  of  Windsor,  England,  in  1856,  a  case  of  typhoid 
fever  was  discovered.  From  lack  of  proper  sewer  ventilation, 
the  foul  and  poisonous  gases  from  the  fecal  matter  of  this  one 
patient,  rising  through  forced  and  siphoned  traps,  caused  the 
death  of  no  less  than  450  other  persons,  all  of  whose  houses  with- 
out exception  were  connected  with  this  sewer.  Windsor  Cas- 
tle, having  its  own  drain,  escaped.  In  another  city,  the  break- 
ing out  of  typhoid  fever  in  the  higher  parts  of  the  town  while  the 
lower  portions  remained  untouched  was  considered  a  mystery 
until  it  was  found  that  the  sewers  not  being  properly  arranged 
allowed  the  poisonous  gases  to  rise  to  the  higher  parts  of  the 


292     ENGINEERING  OF  SHOPS  AND  FACTORIES 

system,  where  they  escaped  and  spread  the  germs  of  disease.  In 
this,  as  in  many  other  cases,  the  community  was  stirred  to  action 
only  by  the  cruel  hand  of  pestilence. 

Flushing  of  Sewers. — When  a  system  of  sewers  is  faulty  either 
in  grade  or  in  size,  special  appliances  for  flushing  should  be 
provided.  One  effective  arrangement  consists  of  an  iron  tank 
fastened  on  trunnions,  having  the  back  end  the  heavier  when 
empty.  On  being  filled  with  water  and  waste,  the  front  end 
becomes  the  heavier  and  it  is  tilted  forward.  ^  It  is  faulty  in 
one  respect,  that  when  in  a  fallen  position  all  matter  issuing 
from  the  sewer  above  it,  will  form  a  pile  of  filth  beneath  the 
back  part  of  the  box.  Other  arrangements  such  as  dams,  etc., 
have  been  used,  but  they  are  insufficient,  since  they  are  not 
self-acting  but  require  constant  attention.  Another  useful 
flushing  tank  for  sewers  has  a  disk  held  in  place  by  the  force  of 
the  water  covering  the  mouth  of  the  sewer  running  from  the 
manhole.  The  sewage  is  periodically  released  by  means  of  a 
chain  fastened  to  a  circular  block,  but  as  a  precaution,  a  float 
is  attached  to  the  chain,  so  that,  should  the  water  rise  to  that 
height,  it  would  liberate  itself.  If,  however,  sewers  are  properly 
arranged  in  other  respects,  they  will  require  but  little  flushing. 
During  hot  summer  months  or  if  fever  is  prevalent,  an  occasional 
cleaning  will  be  necessary.  The  work  should  always  be  begun 
in  the  lower  end,  so  deposits  already  there  will  not  stop  other 
wash. 

Catch  basins  should  be  placed  at  the  corners  of  the  streets 
or  wherever  required,  for  the  purpose  of  arresting  silt  and  solid 
wash  from  the  streets.  In  these  the  iron  over  the  mouth  of  the 
pipe  leading  to  the  sewer  is  hinged  at  the  top  and  is  cemented 
to  the  brickwork  with  plaster  of  Paris,  so  in  case  of  frost  the 
cement  only  will  be  broken,  which  can  be  easily  repaired  in  the 
spring.  Many  engineers  still  prefer  the  method  of  conveying 
street  wash  away  in  a  separate  channel.  These  conduits  may 
be  constructed  in  the  form  of  deep  cast-iron  gutters  covered 
with  a  cast-iron  grating,  the  inner  edge  of  the  gutter  being  carried 
up  to  the  height  of  the  sidewalk.  As  the  accumulated  flow 
requires  greater  cross-sectional  area,  it  should  be  made  in  depth 
rather  than  in  the  width,  which  will  assist  in  keeping  the  gutter 
clean.  The  chief  objection  to  this  method  is  that  in  the  winter 
time  the  crossings  become  coated  with  ice,  but  this  difficulty 


DRAINAGE  OF  INDUSTRIAL  WORKS  293 

is  no  greater  than  that  arising  from  ice  on  the  sidewalks  and 
about  the  catch  basins. 

Pneumatic  System. — All  the  elements  have  been  called  upon 
as  aids  in  the  drainage  of  communities,  including  water,  dry 
earth  and  ashes,  and  now  the  aid  of  compressed  air  is  used  in 
removing  refuse  from  buildings.  On  account  of  its  compara- 
tively recent  discovery,  this  system  is  but  little  used,  but  in 
Holland  and  Austria  where  it  has  been  tried,  good  results  have 
been  obtained.  It  is  to  the  research  and  ingenuity  of  a  Dutch 
engineer  that  the  world  is  indebted  for  the  discovery  of  a 
system  which  has  been  declared  as  the  greatest  modern  invention 
in  sanitary  science.  It  consists  in  having  a  number  of  air-tight 
iron  reservoirs,  as  many  as  the  size  of  the  manufactory  or  village 
needs,  sunk  to  a  sufficient  depth  beneath  the  surface  to  prevent 
freezing,  to  which  are  connected  the  drains  from  the  buildings. 
These  iron  chambers  at  certain  intervals  are  exhausted  of  their 
air,  so  that  when  valves  connecting  with  the  drains  are  opened, 
the  pressure  of  the  atmosphere  forces  everything  from  the  pipes 
down  into  the  central  reservoir.  If  these  pipes  are  numerous, 
they  may  all,  in  the  same  way,  be  emptied  by  a  similar  process 
into  one  central  and  final  vault.  The  chief  difficulty  that  pre- 
sented itself  in  this  undertaking  was  that  some  pipes  would  be 
emptied  before  the  others,  in  which  case  the  air,  finding  easy 
access  through  the  empty  drains,  would  no  longer  affect  those 
which  were  still  full.  But  the  difficulty  was  overcome  by  apply- 
ing the  principle  of  equal  barometric  pressure.  Before  entering 
the  main,  each  building  drain,  has  a  break  or  abrupt  change  in 
elevation  of  say,  exactly  1  ft.  If  one  building  drain  discharges 
a  large  quantity  daily  and  another  supplies  only  a  small  quan- 
tity of  sewage,  then  if  the  air  be  extracted  from  the  main  so 
atmospheric  pressure  acts  in  both  drains,  the  liquid  in  the  first 
will  descend  before  that  in  the  second  begins  to  move.  Then 
when  they  have  both  reached  the  same  point,  the  liquid  in  both 
will  flow  out  together.  In  the  same  way,  no  matter  how  great 
the  number  of  drains,  they  will  all  be  emptied  at  the  same 
instant. 

The  closets  were  originally  simple  iron  hoppers,  placed  where 
possible  one  above  another,  so  the  fall  was  nearly  straight. 
But  other  kinds  may  be  used  equally  well,  provided  a  large  size 
ventilation  pipe  passes  up  through  the  roof  by  which  the  atmos- 


294     ENGINEERING  OF  SHOPS  AND  FACTORIES 

phere  may  exert  its  full  pressure  on  the  liquid  in  the  drain.  As 
the  sewage  at  the  final  depot  is  run  through  sieves,  and  evapor- 
ated for  use  as  fertilizer,  the  street  wash  and  thin  slops  are 
usually  conveyed  by  a  separate  set  of  pipes  into  a  lake  or 
stream. 

The  chief  advantage  of  this  method  above  others  is  that  it 
returns  to  the  soil  that  which  is  .faken  from  it,  and  also  the  in- 
come from  the  sale  of  the  product  soon  pays  for  the  extra  cost 
of  construction. 

Conservation  of  Sewage. — The  earth,  given  by  the  Creator  to 
man,  was  intended  not  as  a  store  house  to  be  pillaged,  but  to  be 
judiciously  used.  With  the  water  system,  refuse  run  into  the 
lakes  or  ocean  is  lost,  as  far  as  the  present  era  of  the  world  is 
concerned.  If  year  after  year  and  generation  after  generation 
the  nourishing  properties  are  extracted  from  the  soil,  the  inevi- 
table result  must  be  impoverishment.  A  city  of  100,000  inhab- 
itants has  a  yearly  provision  supply  of  about  100,000,000  Ib. 
which  is  all  turned  into  the  sewers  and  lost.  This  would  produce 
annually  about  5000  tons  of  dried  excrement.  The  yearly 
amount  of  excrement  from  an  average  inhabitant  is  56  Ib.,  the 
amount  of  organic  matter  in  solid  dried  excrement  being  88  per 
cent,  and  in  urine,  3  per  cent.  But  the  total  daily  amount  of 
organic  matter  from  the  latter  is  about  one-third  more  than 
from  the  former.  Remembering  that  five-sixths  of  the  am- 
monia capable  of  being  generated  from  human  excreta  is  fur- 
nished by  the  urine  and  only  one-fifth  by  the  feces,  and  how 
small  is  the  proportion  of  the  total  urine  passed  at  the  same  time, 
and  that  it  is  impossible  to  collect  all  the  latter,  the  intrinsic 
value  of  the  fertilizing  matter  which  can  be  practically  recovered 
is  probably  not  more  than  one-third  the  value,  or  amounts  to 
75  cents  per  annum  for  each  person,  taking  the  usually  accepted 
value  of  excreta  from  an  average  person  as  $2.25  per  year. 

By  discharging  its  sewage  into  a  lake  or  waterway,  a  city  of 
100,000  loses  annually  no  less  than  $70,000.  Assuming  the 
present  population  of  the  United  States  to  be  90,000,000, 
the  nation  loses  annually  from  this  waste  $60,000,000  to 
$70,000,000. 

Final  Disposal  of  Sewage. — This  is,  perhaps,  of  all  problems  in 
sanitary  science,  the  most  difficult.  Attempts  have  been  made 
to  dispose  of  sewage  by  irrigation,  ignition,  etc.,  but  no  com- 
plete and  satisfactory  method  seems  to  have  been  devised.  For 


DRAINAGE  OF  INDUSTRIAL  WORKS  295 

small  manufacturing  plants  or  industrial  villages  and  for  single 
factory  buildings  the  problem  is  comparatively  simple,  but  in 
large  centers  where  the  quantity  of  solid  and  liquid  refuse  is 
great,  it  is  much  more  complicated.  Sewers  cannot  discharge 
into  a  lake  in  the  vicinity  of  water  works  or  intake,  neither  should 
they  run  into  a  stream  from  which  a  few  miles  further  down 
another  manufactory  or  village  derives  its  supply  of  fresh 
water. 

Perhaps  the  most  successful  solution  yet  presented  for  the 
subject  is  that  of  irrigation.  Experiments  show  that  for  this 
purpose  there  should  be  at  least  one  acre  of  land  for  each  150 
persons.  The  most  suitable  soil  is  a  loose  gravel  thoroughly 
drained  at  a  depth  of  about  6  ft.  below  the  surface.  The  same 
plot  should  not  be  used  continuously,  for  sufficient  time  should 
be  given  at  intervals  for  the  ground  to  become  thoroughly 
aeriated.  On  being  thus  exposed  to  earth  and  air,  all  organic 
particles  become  so  oxidized  that  the  liquid  passes  off  in  a 
comparatively  pure  state,  and  may  with  safety  be  discharged 
into  a  lake  or  stream.  This  system  requires  but  little  time  to 
pay  for  itself,  for  the  amount  of  extra  vegetation  produced 
yearly  on  the  irrigated  soil  has  in  almost  every  case  been  equal 
in  value  to  a  large  proportion  of  the  original  cost  of  land  and 
labor. 

At  Coventry  in  England,  the  liquid  sewage  is  rendered  harmless 
by  mixing  it  with  sulphate  of  alumina.  The  engineer  in  charge 
of  the  works  there  states  in  his  report  that  the  fluid  passing 
off  at  the  rate  of  80,000  gallons  per  hour  was  clear  and  bright, 
and  of  a  high  standard  of  purity.  It  was  without  smell  or 
color  and  at  noon  was  found  to  contain  only  5.85  parts  of  am- 
monia in  100,000  parts.  The  solid  matter  from  the  sewer, 
after  being  separated  from  the  liquid,  is  dried  and  sold  as  a 
fertilizer  for  the  land.  In  order  that  the  discharge  may  be 
more  copious  various  storage  tanks  have  been  devised,  so  that 
when  a  flow  occurs  it  will  be  dispersed  over  a  greater  area  of 
land. 

Another  method  of  sewage  disposal  is  that  of  ignition.  The 
precipitated  sewage  is  first  run  into  shallow  pits  where  it  is  par- 
tially dried,  after  which  it  is  burned  in  large  kilns.  This  method, 
although  producing  no  revenue  from  the  waste,  and  on  the  other 
hand  creating  some  expense,  has  the  advantage  of  immediately 
and  thoroughly  destroying  the  source  of  disease,  which  is  far 


296     ENGINEERING  OF  SHOPS  AND  FACTORIES 

better  than  storing  up  evaporated  excreta  with  the  expectation 
of  selling  it,  and  the  liability  of  spreading  sickness  throughout 
the  country. 

From  the  above  it  appears  that  large  manufactories  instead 
of  incurring  constant  expense  for  the  disposal  of  sewage  can 
cause  it  to  be  a  source  of  revenue,  and  streams  may  continue  pure 
and  clean  instead  of  being  polluted  as  they  so  often  are  with 
dyes  and  refuse  from  shops  and  mills. 


CHAPTER  XXIV 


WATER  SUPPLY  AND  STORAGE  TANKS 

The  four  chief  departments  of  water  supply  are:  (1)  The  source, 
(2)  the  reservoir  or  storage  tank,  (3)  the  pumping  equipment, 
and  (4)  the  distributing  pipes  and  system. 

Water  for  manufacturing  plants  can  be  taken  either  from  some 
established  town  supply,  or  independently  from  an  adjoining 
lake  or  river,  though  springs  or  artesian  wells  are  often  used. 
In  some  regions  such  as  that  adjoining  the  great  watershed  of 
the  Mississippi  river,  or  in  the  western 
arid  states,  artesian  wells  are  common, 
and  the  depth  at  which  water  is  found 
may  vary  from  100  to  3000  ft.  These 
wells  are  usually  8  in.  in  diameter  and 
are  lined  with  wrought-iron  pipe. 

Elevated  tanks  are  valuable  not  only 
for  regular  water  service,  but  for  fire 
protection,  especially  with  automatic 
sprinkler  systems  which  should  always 
be  connected  to  two  separate  water 
sources.  Even  in  towns  and  cities  with 
adjoining  fire  hydrants,  insurance  rates 
are  greatly  reduced  by  the  presence  of 
a  private  pressure  tank.  These  were 
formerly  made  exclusively  of  wood  and 
are  now  to  a  great  extent,  but  as  they 
rarely  last  more  than  twelve  to  fifteen 
years,  they  are  being  replaced  by  steel. 
They  may  either  be  at  ground  level  or 
elevated  on  a  tower,  the  latter  being 

most  effective  when  only  a  limited  water  supply  is  needed,  for 
their  whole  contents  is  then  under  a  higher  pressure  than  if 
standing  on  the  ground.  Some  designs  are  illustrated  in  Figs. 
145,  146,  147  and  148,  the  last  being  of  concrete.  Fig.  149  is 
the  detail  of  a  tank  roof. 

297 


Elevation 

FIG.  145.— Steel    water 
tank   and   tower  at  Paris, 


298     ENGINEERING  OF  SHOPS  AND  FACTORIES 


The  number  of  tower  legs  should  be  proportional  to  the  size 
of  tank,  large  ones  requiring  a  greater  number  than  smaller  ones. 
By  far  the  heaviest  and  most  expensive  part  of  framed  water 

towers  is  the  platform  under  the 
tank,  where  very  heavy  beams 
are  often  needed,  but  this  expense 
may*be  reduced  by  using  a  spher- 
ical bottom. 

They  must  be  strong  enough  to 
resist  the  pressure  of  water,  a 
cubic  foot  of  which,  containing 
7.48  gallons,  weighs  at  62°  F. 
62.36  Ib.  A  gallon  of  water  con- 
taining 231  cu.  in.,  weighs  8.33  Ib., 
and  a  pressure  of  1  Ib.  per  square 
inch  therefore  results  from  a  depth 
of  2.31  ft. 

The  problem  of  water  supply 
may  be  comparatively  simple  in 
regions  near  the  coast  with  large 
precipitation,  but  in  arid  coun- 
tries it  is  often  perplexing,  and  the 
little  water  that  can  be  found 
must  be  collected  and  stored.  In 
the  Eastern  or  Middle  States,  small 
streams  may  often  be  dammed 
at  two  or  three  points,  thus  form- 
ing ponds  or  storage  basins  of  fresh 
water,  but  streams  are  not  always 
available  and  other  methods  must 
be  sought. 

In  order  to  show  some  of  the 
conditions  in  the  arid  states,  and 
the  methods  of  overcoming  them, 

,  a  brief  account  is  given  of  the  in- 
FIG.     146. — Water     tank     and  .  ° 

tower,  Great  Northern  Power  Co.  vestigations   and  plans  made  by 
Height  241  ft.  the  writer  for  supplying  and  stor- 

ing water  for  railroad  shops  and 

locomotives,  at  a  small  town  in  Nevada  on  a  main  line  of  railway. 

The  old  but  insufficient  water  supply  came  from  a  small 

reservoir  on  rising  ground  about  a  mile  north  of  the  railway 


WATER  SUPPLY  AND  STORAGE  TANKS        299 

depot.  The  surface  of  this  reservoir  was  22  ft.  above  the  base 
of  rail  at  the  old  water  tank,  and  from  this  reservoir  a  10-in. 
riveted  iron  pipe  brought  water  down  by  gravity  to  a  30,000 
gallon  wooden  tank  located  about  700  ft.  from  the  depot.  This 


28.490" 


Strain  339.400 

2P18.H"X%»  I 

1  Pis.  17"*  %"  1=29.650" 


Strain  350.100 
2  Pis.  14"x  i 

lPU%17"iJi"  ^30.010' 
2  Ls  3"x  %" 
x  3'i 


FIG.  147. — Tower  for  water  tank. 

tank  stood  on  wooden  posts  and  the  highest  water  in  it  was 
20i  ft.  above  the  base  of  rail.  It  was  used  not  only  for  sup- 
plying locomotives,  but  for  the  workmen's  houses  and  a  few 
fire  hydrants. 


300     ENGINEERING  OF  SHOPS  AND  FACTORIES 

On  account  of  increased  travel  on  the  railway,  and  the  build- 
ing of  large  new  shops  and  round  house,  as  well  as  for  additional 


Z  Pipe 


u fi.Q  on  circle 

Development  of  Circular  Concrete  Girder 


k -I— '-- 

each  Direct/on 

-— -  n-Sa— +* 

FIG.   148. — Water  tank  and  tower  of  reinforced  concrete.     Chicago  City 
Railway  Co.,  Chicago,  111. 

house  service,  the  old  supply  had  become  insufficient  and  it  was 
decided  to  build  an  additional  or  larger  tank,  leaving  the  old 


WATER  SUPPLY  AND  STORAGE  TANKS        301 

one  and  the  pipe  connecting  it  to  the  reservoir  in  their  original 
condition.  In  providing  a  new  tank,  it  was  the  intention  to 
have  a  supply  of  100,000  gallons  of  water  above  the  level  of  the 
spouts  which  deliver  water  to  the  engines,  which  are  about 
12  ft.  above  the  base  of  rail.  It  was  further  intended  to  have 
the  new  tank  with  the  pipe  supplying  it,  independent  of  the  old 
one.  Measurements  of  the  flow  of  water  from  the  reservoir  on 
the  hill  showed  a  daily  discharge  of  190,000  gallons,  which  was 
sufficient  for  both  old  and  new  systems.  An  attempt  to  raise 
the  level  of  the  reservoir  by  banking  it  up  with  earth  had  pre- 


Rods  for  Balusters, 
/       14%'CtoC 


Typical       Section       through       Side 


Section      through      Center     of     Square      Rib 

FIG.  149. — Dome  of  reinforced  concrete  water  tower. 

viously  been  made,  but  instead  of  rising  as  was  expected  the 
water  seeped  away  and  escaped.  It  appeared,  therefore,  that  in 
order  to  secure  a  greater  head  of  water  it  would  be  necessary 
to  go  farther  up  the  valley  and  dam  the  water  at  a  higher  level, 
which  plan  was  not  favored  on  account  of  the  extra  expense. 

Comparative  designs  and  estimates  were,  therefore,  made  for 
several  kinds  of  storage  tanks,  with  a  view  to  selecting  the  most 
economical  and  efficient  one.  The  designs  in  all  cases  have 
steel  tanks,  and  when  towers  are  used  they  stand  on  concrete 
bases,  with  pedestals  of  sufficient  size  under  the  foot  of  each 


302     ENGINEERING  OF  SHOPS  AND  FACTORIES 

column  so  the  pressure  on  the  soil  will  not  exceed  three  tons  per 
square  foot.  As  the  soil  in  this  vicinity  was  sand  and  gravel  it 
was  excellent  for  foundations,  and  the  assumed  unit  pressure 
comparatively  small.  Between  the  pedestals  is  a  layer  of  con- 
crete 12  in.  thick  over  the  whole  remaining  area,  this  feature 
being  desirable,  especially  in  wintej,  when  water  from  leakage 
might  soak  below  the  foundations  and  cause  injury  from  frost. 

Where  the  tanks  rest  directly  on  the  foundation  without 
columns,  the  estimates  provide  for  a  solid  base  of  concrete  4  ft. 
thick  under  the  tanks,  extending  a  foot  outside  of  them  at  the 
upper  surface,  and  stepped  out  still  further  at  the  bottom.  In 
this  case  a  large  part  of  the  cost  is  in  the  concrete,  which  is  about 
four  times  greater  than  for  designs  with  towers.  Instead  of 
using  a  solid  block  of  concrete,  the  cost  might  be  reduced  by 
coring  out  the  center  part  and  filling  it  with  sand.  The  earth 
would  then  be  excavated  to  a  depth  of  3J  ft.  and  a  layer  of 
concrete  laid  12  in.  thick,  with  a  wall  2  ft.  thick  and  3  ft.  high 
around  the  sides,  the  top  of  wall  being  6  in.  above  the  ground. 
After  this  concrete  is  set,  the  inside  part  is  filled  to  a  depth  of  2 
ft.  with  sand  and  gravel,  well  rammed  in  layers  6  in.  thick. 
Over  the  filling  is  then  placed  another  slab  of  concrete  12  in. 
thick,  the  top  being  covered  with  1  in.  of  rich  cement  mortar. 
It  should  be  1  in.  higher  at  the  center  than  at  the  rim,  and  should 
have  occasional  water  gutters  about  1J  in.  deep  formed  in 
the  concrete  for  drainage,  radiating  from  the  center  to  the 
circumference. 

By  comparing  the  designs  it  will  be  seen  that  the  low,  flat 
type  of  tank  is  not  economical,  and,  generally,  the  more  nearly 
equal  are  the  diameter  and  height,  the  less  will  be  the  cost. 
Estimates  in  all  cases  include  roofing  the  tank  over  with  a  wooden 
frame  covered  with  J  in.  sheathing  and  galvanized  iron. 

Comparative  Designs.  Style  A. — This  is  a  steel  tank  10  ft. 
high  and  48  ft.  in  diameter  with  a  capacity  of  100,000  gal- 
lons, standing  on  columns  12  ft.  high  (Fig.  150).  Tank  plates 
are  I  in.  thick,  and  vertical  joints  are  lapped  and  double 
riveted,  but  the  bottom  has  butt  joints  single  riveted  so  the 
tank  bottom  will  have  even  bearing  on  the  beams  or  base. 
Joists  are  7-in.  I  at  15  Ib.  per  lineal  foot,  2  ft.  apart,  rest- 
ing on  15-in.  I  at  42  Ib.,  spaced  9  ft.  apart,  the  whole  floor 
system  being  carried  on  28  columns  each  made  of  four  angles 
and  a  plate.  Diagonal  wind  bracing  is  placed  in  two  direc- 


WATER  SUPPLY  AND  STORAGE  TANKS        303 

tions  at  right  angles  to  each  other.  Inside  of  the  tank  are 
four  light  columns  at  the  four  corners  of  an  8-ft  square, 
supporting  the  roof,  and  these  stand  on  the  bottom  plate 
vertically  over  the  columns  under  them.  The  supply  pipe 


FIG.  150. 


FIG.  151. 


Tank  designs. 


enters  the  tank  through  the  bottom  near  its  center,  and  it  has 
a  gravity  valve.  When  water  in  the  tank  is  drawn  off,  the 
available  or  acting  head  is  increased,  and  the  velocity  in  the 
pipe  is  accelerated,  but  as  the  tank  fills  up  the  head  is  dimin- 


FIG  152. 


FIG.  153. 


Tank  designs. 


ished  and  the  velocity  and  discharge  gradually  decrease.  The 
overflow  pipe  adjoins  the  inlet  and  both  are  enclosed  in  frost 
boxes  made  of  matched  lumber  with  double  walls  6  in.  apart, 
the  space  between  them  being  filled  with  sawdust  tightly  rammed 
in  place.  The  estimated  cost  of  the  complete  structure,  not 
including  pipes  or  connections,  is  $5000. 


304     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Style  B. — This  is  similar  to  A,  and  is  heavy  enough  to  sup- 
port an  additional  height  of  15  ft.  (Fig.  151)  if  such  extra 
capacity  should  be  required  in  the  future.  The  estimated  cost 
of  tank  and  tower  complete  in  position  is  $6200. 

Style  C. — This  is  a  modification  of  the  last  with  the  addi- 
tional 15  ft.  in  height  included  (Fig^  152).  The  tank  will  have  a 
capacity  of  300,000  gallons.  To  fill  a  tank  of  this  height,  either 
a  reservoir  must  be  placed  at  a  higher  level  from  which  it 
would  be  filled  by  gravity,  or  a  small  pumping  ^plant  installed. 
The  cost  of  a  pump  with  a  sump  and  1000  ft.  additional  pipe 
to  connect  the  tank  with  the  engine  room  where  the  pump  would 
be  placed  is  about  $800.  This  amount  added  to  the  cost  of  the 
tank  itself  makes  the  total  cost  of  both  about  $8300. 


- 

r 
^^-—  —  -^_ 

1 

[ 

j 

FIG.  154.  FIG.  155. 

Tank  designs. 

Style  D. — It  resembles  Style  A  excepting  that  the  tank 
stands  directly  on  the  concrete  foundation  (Fig.  153)  instead  of 
being  elevated  on  columns.  The  amount  of  water  stored  in 
this  tank  above  the  level  of  the  locomotive  feed  is  no  greater 
than  for  A,  but  the  total  amount  is  about  300,000  gallons,  and 
the  extra  supply  can  be  used  to  advantage  in  the  watering  of 
cars  and  for  use  around  the  engine  house  and  machine  shop.  The 
cost  including  a  solid  concrete  base  4  ft.  thick  is  $6100. 

Style  E. — This  is  similar  to  the  last,  but  is  made  sufficiently 
strong  to  support  an  additional  15  ft.  in  height  in  case  it  should 
be  needed.  The  estimated  cost  is  $7300  (Fig.  154). 

Style  F. — In  this  estimate,  the  15  additional  ft.  in  height 
referred  to  in  the  last  is  included,  making  the  total  capacity  about 
450,000  gallons.  The  estimated  cost  including  the  necessary 
pumping  outfit  is  $9400  (Fig.  155). 

Style  G. — All  the  previous  designs  have  had  a  diameter  of 


WATER  SUPPLY  AND  STORAGE  TANKS        305 

48  ft.  but  this  one  (Fig.  156)  is  reduced  to  28  ft.  and  28  ft.  high 
of  the  required  size  to  hold  100,000  gallons.  It  stands  on  col- 
umns 12  ft.  high,  and  only  one-third  of  its  capacity,  or  about 
30,000  gallons  can  be  filled  by  gravity  from  the  old  reservoir. 
The  remaining  two-thirds  must  either  be  pumped  or  come  from 
a  reservoir  at  a  higher  level.  In  this  case,  as  in  C  and  F,  the 
estimate  includes  an  item  of  $800  for  a  pump  and  its  equipment. 
If  this  pump  should  be  out  of  order  at  any  time,  the  tank  will 
still  contain  30,000  gallons  of  water,  supplied  from  the  old  reser- 
voir by  gravity,  which  amount  is  equal  to  the  whole  capacity 
of  the  old  wooden  tank,  and  would  temporarily  be  sufficient  to 
meet  the  ordinary  demand  of  locomotives.  Without  any  re- 
serve supply  the  estimated  cost  of  this  design,  including  the 
pumping  outfit,  is  $4200. 


FIG.  156.  FIG.  157. 

Tank  designs. 

Style  H. — This  is  similar  to  Style  G,  excepting  that  instead 
of  supporting  the  tank  on  steel  columns,  it  stands  directly  on  a 
concrete  base  (Fig.  157),  thereby  increasing  the  storage  capacity 
to  150,000  gallons.  The  estimated  cost  of  the  structure  complete 
and  in  position,  including  the  pump  and  accessories,  is  $4500. 
It  is  28  ft.  in  diameter  and  40  ft.  high,  and  will  always  contain 
at  least  30,000  gallons  of  water  above  the  locomotive  spouts, 
as  this  height  will  be  maintained  by  gravity.  The  extra  height 
of  about  20  ft.  can  be  filled  by  a  centrifugal  pump  with  4-in. 
suction  and  delivery  connections,  which  will  be  located  in 
the  machine  shop  convenient  to  the  main  driving  shaft.  The 
pump  would  cost  $150  and  is  guaranteed  to  deliver  200,000  to 
300,000  gallons  per  day,  but  with  this  capacity  it  need  be  in 
operation  only  during  regular  working  hours  or  a  portion  of 
them.  If  it  should  ever  become  necessary  to  keep  the  pump 
20 


306     ENGINEERING  OF  SHOPS  AND  FACTORIES 

in  constant  operation,  a  small  8-h.p.  engine  might  be  installed 
at  an  additional  cost  of  about  $200. 

The  tank  is  supplied  by  an  independent  line  of  riveted  steel 
pipe  10  in.  in  diameter,  running  from  the  old  reservoir  about  one 
mile  up  the  valley,  and  connecting  to  a  cast-iron  sump  box  or 
cistern  under  the  machine  shop  floor.     The  sump  has  a  movable 
top  which  can  be  taken  off  for  Cleaning  or  removing  deposit 
that  may  have  come  down  the  supply  pipe.     It  is  permanently 
under  the  pressure  of  a  22-ft.  head  of  water,  and  from  it  a  cen- 
trifugal pump  forces  water  into  the  storage  tank.     Valves  are 
provided  on  each  side  of  the  sump  to  shut  off  the  flow  of  water 
in  the  pipes.     The  supply  enters  the  tank  from  the  bottom,  so 
it  will  be  filled  up  to  the  20J-ft.  level  by  gravity  before  pump- 
ing is  needed.     By  connecting  the  supply  pipe  to  the  bottom 
the  greatest  velocity  is  secured,  and  when  water  in  the  tank  is 
low  it  fills  again  at  a  greater  speed  than  when  tank  and  reser- 
voir are  approaching  the  same  level.     No  frost  boxes  or  other 
pipe  protection  are  required,  as  the  pipes  are  embedded  in  the 
concrete  below  the  level  of  the  ground.     The  estimated  cost  of 
$4500  includes  a  solid  block  of  concrete  4  ft.  thick,  but  this  cost 
may  be  reduced  by  coring  out  the  central  part  as  previously 
described,  and  filling  it  with  solid  sand  and  gravel.     The  valve 
over  the  supply  pipe  in  the  bottom  opens  upward  so  that  water 
may  always  enter  and  it  is  kept  closed  by  gravity  and  by  the 
weight  of  water  above  it.     A  10-in.  supply  pipe  under  a  head  of 
only  2  ft.  will  deliver  water  at  the  rate  of  2.9  cu.  ft.  or  21  gallons 
per  second,  which  is  more  than  sufficient  to  keep  the  tank  con- 
tinuously and  adequately  supplied.     It  is  covered  over  with  a 
conical  roof,  framed  with  wood  and  covered  with  galvanized  iron. 
Selection  of  Style. — The  considerations  in  selecting  a  design 
from  the  several  possible  ones  are  that  it  should  contain  enough 
water  to  supply  eight  to  ten  locomotives  daily  in  both  directions, 
or  a  total  of  sixteen  to  twenty,  the  average  capacity  of  their 
tanks  being  40,000  gallons.     There  must  also  be  enough  water 
to  replenish  car  tanks  on  the  passenger  trains.     The  round  house 
will  require  water  for  cleaning,  and  the  machine  shop  and  boiler 
room  attached  thereto  will  need  from  15,000  to  20,000  gallons 
per  day  for  the  boilers  and  general  service.     The  hotels  and  other 
houses  must  also  be  supplied,  and  adjoining  the  railroad  depot 
is  a  fire  plug  which  may  at  any  time  be  brought  into  active 
service. 


WATER  SUPPLY  AND  STORAGE  TANKS        307 


Choice  must  also  be  made  between  gravity  supply  and  pump- 
ing. A  gravity  system  is  usually  preferred,  because  it  requires 
no  attention  and  there  is  no  machinery  to  break  down  or  become 
disordered.  Of  the  four  designs  considered,  in  which  water 
supply  must  come  from  a  higher  reservoir  or  be  forced  up  with 
pumps,  the  natural  supply  is  greatly  preferred  and  a  higher 
basin  may  be  built  at  any  time  in  the  future  and  pipe  connection 
made  thereto.  A  suitable  site  for  such  a  water  basin  could  be 
found  2  or  3  miles  farther  up  the  valley  at  a  place  where  the 
hills  converge,  where  the  head  would  have  an  additional  height 
of  200  ft.  The  cost  of  this  reservoir  and  the  2  or  3  miles  of  pipe 
would  be  from  $4000  to  $5000,  while  the  pumping  plant  can  be 
installed  for  an  additional  cost  of  only  $800.  The  reason  for 
the  low  cost  of  a  pumping  plant  is,  that  the  machine  shop 
adjoining  the  round  house  which  is  only  500  ft.  from  the  proposed 
water  tank,  is  already  equipped  with  power,  and  the  only  addi- 
tional machinery  needed  is  a  pump  which  may  be  run  by  belt 
from  the  overhead  shafting. 

The  third  consideration  in  choosing  from  the  possible  types 
described  above  is  the  matter  of  cost,  a  summary  of  which  is 
given  in  the  following  schedule: 


Cost 

Capacity  in  gallons 

Style  A  
Style  B 

$5000 
6200 

100,000 
100  000 

Style  C  

8300 

300,000 

Style  D 

6100 

300  000 

Style  E  
Style  F 

7300 
9400 

300,000 
450  000 

Style  G  

4200 

100,000 

Style  H  

4500 

150  000 

In  selecting  a  tank  from  the  eight  designs  considered,  Style 
H,  for  a  tank  40  ft.  in  height  and  28  ft.  in  diameter,  standing 
on  a  solid  concrete  base,  offered  the  greatest  advantages  and 
was  therefore  chosen.  Its  comparative  merits  have  previously 
been  given. 

Other  designs  for  water  tanks  or  stand  pipes  are  shown  in 
Figs.  158,  159  and  160. 


308     ENGINEERING  OF  SHOPS  AND  FACTORIES 


HALF  ELEVATION  VERTICAL  SEXTON 


FIG.    158. — Steel  and  concrete  water  tank  at  Grand   Rapids,   Michigan. 
Capacity  885,000  gallons. 


WATER  SUPPLY  AND  STORAGE  TANKS       309 


FIG.  159. — Reinforced  concrete  stand  pipe,  Westerly,  R.  I. 


4o'Dia.Cylinder,  OO'Higb,    Thickness  Lower  Plates  for  Hydrostatic  Pressur 
Circumference  125.60,'      Diain.  40'  x  H.  Ou'  x  62.5  Lbs.  .    60,000  x  12"x 


Area  1256.64  Sq.Ft. 

60 


•     4.8  Fact.  Safety 
60,000  Lbs.  Unit  Stress 
V3  Joint  Efficiency 
4.8  Factor  Safety 

Estimated  Weight  of  Stand  Pipe. 

Side  Sheets  144,048  Lbs 

Bed  Plate  32,028    •« 

ButtJointStra.ps.      .Approx.  12,000   •• 

Rivets  »»  14,000  " 

Angles,  Balcony  etc.       ..  15,000  •' 

108  Tons  ±  217,076  " 

Contents 
1256  Area  x  60  =  75.360  Cu.Ft.  at  6%  Lb.  =      4,710.000  " 


'Diam.  by  3'Thick=  177  Cu.Vds.  at  3700  Lb.=  654,900  « 
2791.00  Tons.  5,581,976  • 

Bearing  Surface  Foundation 
£  45' Diam.  =  1590  1  Sq  Ft. 

5,581,070  Lbs.— 1500.4  Sq.Ft.  =  3511  Lbs.  per 
'  Sq.Ft.=  1,755  Tons  Dead  Load. 


I 


Overturning  Moment  of  Wind 

10' x  60'=  2400  Sq.Ft.  x|30  Lbs.  Pressure=30  T( 

36  Tons  by  30  Leverage*  1080  Ft.-Tons 

Resistance  to  Overturning 
Weight  Leve.aga     | 

108  Tons    x     20'=  2100  Ft.-Tons 


l\ 


FIG.  160. — Stand  pipe  stress  sheet. 


310     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE  XXIV.— STANDARD  DIMENSIONS  FOR  ROUND  BOTTOM  STEEL  TANKS 


Capacity  in 
gallons 

Outside  diame- 
ter in  feet 

Height  of  tank  side  not  including 
curved  bottom 

Ft. 

In. 

10,000 

11 

10 

0 

15,000 

12 

14 

0 

20,000 

13 

16 

0 

25,000 

14 

17 

0 

30,000 

15 

18 

0 

35,000 

16 

18 

0 

40,000 

17 

18 

0 

45,000 

17 

21 

0 

50,000 

18 

20 

4 

55,000 

18 

23 

0 

60,000 

19 

22 

0 

65,000 

19 

24 

4 

70,000 

20 

23 

0 

75,000 

20 

25 

3 

80,000 

21 

24 

0 

90,000 

21 

27 

9 

100,000 

22 

28 

0 

125,000 

24 

29 

0 

*-    150,000 

25 

32 

6 

175,000 

26 

35 

5 

200,000 

28 

34 

1 

250,000 

30 

37 

4 

300,000 

32 

39 

3 

WATER  SUPPLY  AND  STORAGE  TANKS        311 


TABLE    XXV.— CAPACITY    OF     CYLINDRICAL     TANKS,    INCLUDING     HEMI- 
SPHERICAL BOTTOM 


Diameter 
in  feet 

Capacity  in  gallons  per 
vertical  foot 

Capacity  in  gallons  of 
hemispherical  bottom 

5 

146.9 

244.8 

6 

211.5 

423.0 

7 

287.9 

671.8 

8 

376.0 

1002  .  7 

9 

475.9 

1427.1 

10 

587.6 

1958.3 

11 

710.9 

2606.6 

12 

846.0 

3384.6 

13 

992.9 

4302  .  6 

14 

1151.5 

5373.7 

15 

1321.9 

6609  .  5 

16 

1504.1 

8021.9 

17 

1697.9 

9621.4 

18 

1903.6 

11421.6 

19 

2120.9 

13432.4 

20 

2350.1 

15667.3 

21 

2591.0 

18137.0 

22 

2843  .  6 

20853.1 

23 

3108.0 

23828.0 

24 

3384  .  1 

27072.8 

25 

3672.0 

30600.0 

26 

3971.6 

34420.5 

27 

4283  .  0 

38547.0 

28 

4606.2 

42991.2 

29 

4941.0 

47763.0 

30 

5287.7 

52877.0 

312     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TH 

O3t^<N           «O    CO    (N                           OOOOCO 

THrHCO               O     t^-     "O     TH                TH     <M     CO     OS 

C^    CD    00           CO    TH    CD    00           O    C4    TH    CD 

t5    CD   S    CO 

CO    00     TH     rH 

<N    CO    CO    CO 

OS    OS    <M    CO 
CO    TH    iO    CO 

CO    O 
CO   t-    >O   00 

rH     00    t>-    t>- 

00    OS     rH     CO 
rH    rH 

1 

n 

0 

<N    <N    (N 

00   CO   *   00 

IM    rH    <M    00 
CO   00    *O   O 
CO    O   CO    »O 

§0?OS 
00    CS|    t^    TH 

s 

H 

M 

CO   00   OS    —! 

OQ 

fr| 

1 

00 

i-H 

OOCOCD           l^    O    CO    00           CO    00    LO   C^ 
rHTHCO             OSrHdCO             lO    CO    00    O 

IM          >O 

00          CO    <N 
00   TH    CO   Is- 

}OS   CO   OS    O 

rH    QO 

'O    (N 

23553 

H 

O 

(N   (N   <N   (N 

(N   CO   CO   >O 

CO  t^   00   O 

3 

P 

>/• 

i 
1 

CO 

III  III1  siis 

rj<          (N 

00   TH   00   OS 
»O   (N    OS   Is- 

CO    CD   00   O 
CD   (N   TH    TH 

S3    CO    (N 

rH    00    CO   OS 

TH     IO    00     rH 

^ 

lO   CO   t^    OS 

PH 

1 

H 

| 

a 

i 
i 

1C 
rH 

III  =g|2  gill 

(N           CO 
CO    <N    TH    CO 

CO    OS    >O    (N 
CO    OS    i-H    CO 

OS    CO    TH    rH 
OS    CO    CD    CO 

ITHCO 

rH     rH     CO     CD 

rH 
Q 

>O   CO  t>    00 

1 

TH 

TH    »O   O           CO    LO   CO   Is-          OS    rH   CO   Is- 

CO    OS    O    00 

rH     1C    rH     CO 
t>-    00    O     rH 

III! 

OS   TH    (N 
CO   >O    >O   ^ 
l>   l^    00   O 

O 

d 

0) 

(N    (N    CO    CO 

TH    IO    CO   00 

0 

1 

JM 
| 

rH 

rHCOTH             CDt^OOOS             O    rH    <N    CO 

00   CO    iO   CO 

(M           (N   00 

00  co  i>  os 

O   OS    00   00 

PH 

A 

T*      TH      LO      CO 

fe 

I 

rnrHT,                      rHVOrH 

0          TH 

OS 

8 

0 

0*010           THrHOOCO          IO    CO    <N    <N 
rH    <N    CO             IO    CO    CD    Is-             OOOSOrH 

<M    04    CO   TH 

(N    CO    TH    IO 

CD  o  I-H  r^ 

rH     OS     TH 
TH     rH     00     f^ 

e 

pj 

§ 

| 

1 

OS 

1s-    CO    rH           COCOCOCO                   COCO 
COrHCO           OS    (N    OS    O           LO    CO    >O    i-H 

O    <N    CO           TH    LO   CO    CO           Is*    00    OS    O 

O    OS    OS    OS 

rH     rH     (N     CO 

Os   t**-   00   00 
OS    CO    >O   t>- 

rH    00    OS    TH 

CD   (N    S    ° 

0     t-     TH     rH 

2 

0) 

rH 

CO    CO    TH    iO 

g 

O! 

In 

oo 

III  111!  8!11 

C<l           00 

00          00   (N 

CO   CO    TH    O 
CO    CO   t^   <N 

(N     OS     rH     OS 

t^    (N   OS   >O 

p; 

| 

H 

W 

3 

CO 

LO    CO    TH             TH    TH    rH    <N                      IN    rH    TH 
OrHIN           COCOTHTji           »O»OCDCD 

TH   00   O   rH 

Sii§ 

lil! 

sl§3 

EH 

rH     rH     rH 

<M    <N    (N    CO 

Diameter  of 
cylinder, 
inches 

i-HINCO           THTHTHTH           IOIO>O»O 

CO    CO    CD   CO 

nH< 
l>   I>    00   OS 

O    rH     (N     CO 

WATER  SUPPLY  AND  STORAGE  TANKS        313 


' 

§88     8§8 

§88 

88S 

88S 

8§8 

888 

88 

rH     rH              <N     IN     CO 

CO   •*   Tt< 

1C   CD   l> 

OS   O   (N 

2rH§ 

1C   O  1C 
(N   CO   CO 

3§ 

'£ 

in 

o 

Tt<   00   CO          b-   rH   CD 

O    1C    OS 

CO    IN    1C 

GO    b-    OS 

rH     rH     1C 

00   IN   CD 

8  t2 

O 

£ 

1C 

CO 

rH          rH   IN   <N 

CO    CO    CO 

Tt<    1C   CO 

b-   00   O 

CO    1C    b- 

rH     CO    O 

<N   (N    CO 

1C   CO 
CO   •* 

H 

b-   iC   <N          O  b-  iC 

CO    t>    r-l             1C    00    <N 

(N   O   t^ 

CO   0   CO 

i2SS 

1C   O   b- 

b-   1C   CO 

1C    <N     O 
<N     rH    O 

1C  O  1C 
b-   1C   C\l 

8S 

1 

c. 

rH             rH    rH    IN 

<N   CO   CO 

CO   •<*   1C 

CD  b-   OS 

rH    CO    1C 

00    (N    CO 

rH     <N     <N 

CO   CO 

fe 

rH   IN   Tf          1C   CO   b- 
CO   CO   OS          <N    1C   00 

O5   O   rH 

rH     1C    00 

(N    1C   OS 
rH    t>    CO 

IN     1C    rH 

CO   <N   00 

b-    ^    O 
CO    OS    1C 

(N   1C   b- 
b-    b-    00 

§iC 
IN 

P 
0 

i 

r-l    r-l    rH 

N   <N   C^ 

m  <n  *n 

1C  CD  b- 

OS   0   (N 

1C     00     rH 
rH    rH    IN 

1C     rH 

(N   CO 

8§£     8S8 

1C   O   iC 
K.O   (N 

1C  O  l> 

§88 

§£8 

§8§ 

88 

<5 
•-». 

§ 

rH    rH    rH 

rH    (N    (N 

(N   CO   CO 

•*    1C    CO 

b-   00   O 

(N   1C  b- 

S8 

p 

W 

•    1C 

(N     Tjl     CO              b-     OS    rH 

(M    ^    CO           00    O    CO 

CO    1C   O 

1C   l>   OS 

OS   (N   00 
tH    CO    d 

rj*    b-    b- 

OS    CO    -^f 

CO   CO   1C 
1C   CO   b- 

S  M   S 

OS    rH    CO 

§io 

ffi 

a 

rH 

CO  b-  CO 

O   CO   1C 

rH^ 

8 

s 

OS   b-    CO           1C    -5j<    C<l 
TH    CO    1C            b-    OS    rH 

rH    O    O5 
CO    1C    CO 

t^    1C    rH 
00   IN   00 

b-    1C    OS 
CO    b-    CO 

(N   CO  O 
CO   1C   1C 

b-   1C   IN 

CO     (N     r-5 

SiC 
b. 

Q 

a 

y> 

rH    rH 

1C   00 

ft 

p 

1C 

rH    CO    •<*!             CO    b-    OS 

O  <N   •>* 

1C   00   CO 

00     rH    OS 

CO    TJH     (N 

00   CO   OS 

§  s 

§ 

d 

<N   CO   CO 

•*   1C  CO 

b-  OS  O 

IN   >C 

rt 

H 

^ 

8 

C^|   1C   b-          O   iM    1C 

rH    (M    CO           1C    O    1> 

l>   O   <M 

00     O     rH 

1C  O  b- 

<N    1C   00 

1C    O    IN 
IN    1C    rH 

1C  b-  O 

b-    CO    O 

iC  O   1C 
(N    1C   b- 

8§ 

I 

rH 

W 

1 

K 
j 

1C 

l> 

§OS    00           b-    b-    CO 
rH     (M              CO     Tt*     1C 

CO    1C    ^ 

CO   t^   00 

S3  3 

rH     rH 

00    b-    •* 

CO   00   CO 

r-l    rH    (N 

rH     00     1C 

00  (N   b- 

(N   CO   CO 

OS   IN   CO 
CD   CD   1C 

-*   1C   CO 

1C    CO 
b^   OS 

§ 

o 

SIN     OS              1C    rH    b- 
rH     rH              (N     CO     CO 

3S8 

(N     1C    -^ 

CO    b-    OS 

IN   1C   CO 

rH     IN     1C 

fe2§ 

(N    >C   b- 

rH    b-     CO 

§1C 
(N 

H 
M 

rH     rH     rH 

rH    W    (N 

CO   CO   •* 

1C    CO 

E 

1C 

rH    <N    •*           1C    CO    b- 
CO   CO   OS          IN    iC   CO 
O    O    O             rH    rH    rH 

2SS 

W   (M    (N 

(N    JC   OS 

rH    b-     CO 
CO     CO     Tj< 

HIS 

§il 

(N   1C   b- 

CO   b-    00 

O   1C 
O   <N 

J 

rH    rH 

rH    rH    (N 

IN   CO 

X 

0 

(N   1C   b-          O   IM    >C 

3§S     S§^ 

l^   O   iM 

0     2     rH 

1C   O   b- 
IN    1C    00 

1C   O   (N 

(N     1C     rH 

(N    (N    CO 

1C    b-    O 

b-    CO    0 
CO   •*   1C 

1C   O   1C 

s^So 

8§ 

O   (N 

« 

w 

rH    rH 

TABL 

(Jrallons  per 
minute 

^22     SSc^ 

1C     O    1C 

CO   -^   •* 

O    O    1C 
1C    CO   b- 

SO   1C 
O   (N 

SSI 

8SS 

Tfl     *O 

314     ENGINEERING  OF  SHOPS  AND  FACTORIES 


lO    O5 

l-H      O 

1-1    <N 


£gi 


s 


CO 


O5    00 

CO    *O 


o       ° 

CO  00 


§    * 

CO 


£553 


s 


-H     O5    CD 


oo  oo  o 


oo  o  oo 

CO    iO    CD 


:S 

ii 

•    o> 


,lj 

•     O)    n3 

S^5 


w 


r^         w  O      T! 

—  ^         £H         OJ 

oT  o         °    08    gc 
s    3     »  J§   S   3 

|  gg  g  .5?^  ij 

1, 1,^^  3« 

07      05      g    "3      g      CO 

S  g  4»  '•?  -r 

o    o  N    «  ^  ^ 

££     >  w  o 


WATER  SUPPLY  AND  STORAGE  TANKS        315 


•  •   O      •   <N      •   TJ<      •  bt      -Old 

•  •  o    •  d    •  d    •  d    -do 

§•   CO       •   i— I       -CO      •   00   b» 
•   CO       •   b-       •   <N       •   00   CO 

\  d    •  d    |  d    •  d    |  d  d 

r-l          -CO          'CO          -CO          •     CO     1-H 

O       •   O       •    r-l      •   <N       •   CO   »O 

•  •  o     •  d     •  o     •  d     -do 

r-l         -IN         -CO^OOCOOO500O5COb-r-l 

O      •   O      -OOOr-iiMlNCO^CDb-r-i 

d    •  d    -ddddddddddi-H 
dddddddddddr-H    - 

ddodddddtHiN 

:     -d     -d     |dddddddcNco 

•    O5       -CO       •    OJ       '(NOlCOiOCOr-ICO       • 

•   T->      .   TJH      .   os      -CO      •   rt<   CO   ^   O5  (N   i-l  "5      • 

i-lCMiMCO 

rH    ?q    CO        ••••••• 

r-l    1C   00    b-    O    1C 

rHrH<N<N<M 

THCOOOCOOiOOO       •       •       •       •       •       •       •       •       •       •       • 

OOrHOi 

00  O  b-  -*ti  O 

l-T  i-T  rH~  r-T  W     C^T  Of  CO*" 


i 


CHAPTER*  XXV 

STEEL  CHIMNEYS 

l. 

This  type  of  stack  is  used  chiefly  for  lofty  ones  with  heights 

of  150  to  300  ft.  They  have  the  advantage  of  occupying  small 
space,  and  costing  30  to  50  per  cent,  less  than  brick.  The  effect 
of  wind  on  cylindrical  surfaces  is  only  half  as  great  as  on  flat 
ones  of  the  same  width,  and  in  metal  stacks,  the  overturning 
tendency  may  be  resisted  by  increasing  the  bottom  diameter. 
This  obviates  the  use  of  unsightly  guy  ropes,  which  at  once 
betray  their  weakness.  They  should  be  proportioned  for  a  wind 
pressure  of  50  Ib.  per  square  foot,  corresponding  to  a  velocity  of 
100  miles  per  hour.  The  small  weight  of  steel  draft  stacks  pro- 
duces a  corresponding  saving  in  the  cost  of  the  foundations.  One 
300  ft.  in  height  would  have  a  bottom  wall  thickness  of  55  to 
60  in.  in  brick,  and  18  to  24  in.  in  reinforced  concrete,  requiring 
greater  width  and  sustaining  power  in  the  foundation.  Metal 
stacks  can  be  erected  much  more  rapidly  than  masonry,  and  an 
ordinary  one  100  ft.  in  height  should  easily  be  completed  within 
thirty  days.  They  have,  however,  the  disadvantage  of  requiring 
frequent  painting,  at  least  once  every  four  years  (Fig.  161). 

Their  required  height  depends  somewhat  on  the  surroundings, 
and  the  elevation  of  adjoining  hills  and  buildings,  and  they  are 
more  effective  on  high  ground  than  in  a  valley.  But  their 
height  should  always  be  at  least  twenty  times  their  inside 
diameter. 

The  need  of  lining  will  depend  largely  on  the  proximity  of  the 
boilers,  because  when  removed  from  the  source  of  heat  the 
smoke  and  gases  will  have  cooled  enough  before  reaching  the 
stack  to  make  lining  unnecessary.  Some  builders  make  a  prac- 
tice of  lining  all  stacks  exceeding  75  ft.  in  height,  and. reinforced 
concrete  is  now  being  much  used  for  this  purpose. 

With  the  relative  proportion  of  diameter  and  height  as  given 
above,  the  thickness  of  plates  should  be  according  to  the  follow- 
ing table: 

316 


STEEL  CHIMNEYS 


317 


Joints. 

Shoulder       and        Foundation 
Pfate        Connection         Details 


Vertical    Section 
through    Flue. 


Plan      of     Bell     and 
Foundation  Plates, 

Enlarged. 


FIG.  161.— Steel  chimney  for  the  St.  Louis  Transit  Co.     Height  202  ft. 


318     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Upper    40  ft.  of  stack  should  have  plates  3/16  in.  thick. 

40  to  60    ft.  below  the  top,  plates    1/4  in.  thick. 

60  to  80    ft.  below  the  top,  plates  5/16  in.  thick. 

80  to  100  ft.  below  the  top,  plates    3/8  in.  thick. 

100  to  120  ft.  below  the  top,  plates    1/2  in.  thick. 

The  width  of  base  should  usually  be  increased  to  twice  the  upper 

diameter,  the  change  starting  at  a  height  of  five  diameters  above 
the    foundation    (Fig.   162).     Up  to  200  ft.   in 
height,  the  average  cost  should  not  exceed  $10* 
to  $15  per  vertical  foot. 

A  ladder  should  be  placed  on  the  outside  for 
use  when  painting,  and  a  circular  trolley  track 
near  the  top,  standing  out  a  few  inches 
from  the  cylinder,  will  permit  workmen  on  a 
suspended  platform  to  move  themselves  about 
to  any  desired  position.  The  whole  appearance 
is  improved  by  the  addition  of  a  neat  orna- 
mental iron  top  with  projecting  cornice. 

A  cheaper  type  of  metal  stack  may  be  made  in 
rectangular  form,  framed  with  structural  shapes, 
and  lined  inside  with  corrugated  iron.  Angles 
are  convenient  for  corner  members,  and  chan- 
nels for  the  horizontal  girths,  which  should  be 
placed  about  9}  ft.  apart  vertically,  for  10- 
ft.  metal  sheets.  They  must  usually  be  guyed 

FIG  162— Chim-  at   intervals    of  about  30  ft.   apart  vertically, 
ney  diagram.       One  of  this  form,  190  ft.  in  height,  and  10  by 
12    ft.   in    sectional   area,   erected  at  Garfield, 

Utah,  weighed  55,000  Ib.  and  cost  less  than  $4900,  equivalent 

to  8.8  cents  per  pound. 


CHAPTER  XXVI 
FIRE   PROTECTION 

The  need  of  adequate  fire  protection  can  best  be  shown  by 
reference  to  statistics.  During  the  year  1907,  which  was  free 
from  any  great  conflagrations  such  as  those  which  visited  the 
cities  of  Chicago,  Baltimore  and  San  Francisco,  the  fire  loss  in 
the  United  States  was  as  follows: 

Property $215,000,000 

Lives  lost 1450 

Persons  injured 5650 

About  two-thirds  of  the  above  loss  was  from  wooden  buildings. 
Reports  from  the  insurance  companies  show  that  there  are 
annually  about  2000  fires  in  manufacturing  buildings  in  the 
United  States,  resulting  in  losses  of  $25,000  or  more,  each, 
making  a  yearly  loss  equal  to  $2.50  for  every  living  person  in 
the  country.  At  least  one  quarter  of  these  fires  include  more 
than  one  building.  Reports  from  seven  large  cities  of  Europe 
reveal  a  much  smaller  loss,  the  average  being  only  30  cents  for 
each  inhabitant. 

Fire  loss  is  relatively  small  in  plants  which  are  built  and 
equipped  according  to  the  standard  regulations  of  the  fire  insur- 
ance companies,  the  average  for  ten  years  being  only  4  cents  per 
$100  of  value,  while  in  plants  devoid  of  such  protection  the  loss 
is  about  60  cents  per  $100.  While  fires  cannot  be  entirely  avoided, 
it  is  now  well  known  that  by  taking  the  proper  precaution,  at 
least  60  per  cent,  of  them  would  never  occur.  Insurance  is 
merely  a  means  of  ready  relief  to  the  first  loser,  but  when  viewed 
in  a  wider  light  it  only  distributes  loss  among  a  greater  number 
of  persons,  the  total  to  the  community  remaining  the  same. 

Methods  of  Protection. — Fire  protection  is  secured  in  several 
ways,  some  of  which  are 

1.  Use  of  fireproof  building  material. 

2.  Separation  of  stories  and  departments. 

3.  Installation  of  fire-fighting  appliances. 

4.  Frequent  inspection; 

5.  Fire  drill. 

319 


320     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Fireproof  Materials. — The  best  way  to  prevent  fire  is  to  make 
the  building  as  nearly  fireproof  as  possible.  Timber  should  be 
in  large  sizes,  and  framed  according  to  the  standards  of  "  Slow 
Burning  or  Wood  Mill  Construction"  which  is  described  else- 
where. When  in  large  sizes,  timber  is  decomposed  very  slowly 
in  a  fire,  and  it  has  been  found  much  safer  than  unprotected 
steel.  In  comparing  Slow  Burning' Construction  with  the  older 
type  having  small  joist  16  to  18  in.  apart,  as  in  residences,  a 
floor  with  heavy  framing  will  last  five  to  ten  times  as  long  in  a 
fire  as  one  with  joist.  Comparative  tests  of  two  buildings  under 
similar  conditions  showed  that  the  heavy  framing  stood  for 
twenty  minutes  in  the  same  fire  that  caused  joists  to  collapse 
in  less  than  three  minutes.  Wooden  walls  may  be  25  per  cent, 
cheaper  than  brick  and  require  less  expensive  foundations,  but 
when  used,  small  pieces  that  will  easily  burn,  should  be  avoided. 

Unprotected  steel  must  not  be  used,  but  must  be  covered  with 
fireproof  material  such  as  brick,  terra-cotta  or  concrete,  though 
a  better  way  is  to  make  the  whole  building  of  concrete.  Stone  is 
not  reliable  in  fire,  for  it  splits  and  cracks  and  is  quite  inferior 
to  brick  or  concrete. 

Roofs  should  be  as  nearly  fireproof  as  possible,  especially 
over  fires,  or  adjoining  stacks  or  flues.  If  the  uncovered  hand 
cannot  be  held  against  a  hot  pipe  it  is  not  safe  to  be  in  contact 
with  wood,  for  when  framing  becomes  thoroughly  dry  it  is  in 
greater  danger  of  taking  fire.  Chimneys  where  they  pass  through 
the  roof  should  be  surrounded  by  a  metal  hood.  A  flue  is  not 
always  hottest  near  the  furnace,  for  some  of  the  gases  may  not 
fully  ignite  until  reaching  the  open  air.  Pipes  are,  therefore, 
often  hotter  near  the  top  than  adjoining  the  furnace.  If  a  pipe 
should  endanger  the  roof,  the  danger  may  sometimes  be  lessened 
by  lengthening  it. 

Small  framing  members  such  as  are  frequently  found  in  sky- 
lights, ventilators,  gutters,  and  louvres,  should  be  avoided,  as 
they  easily  catch  and  hold  fire,  and  the  roof  exterior  should  be 
well  covered  with  some  such  covering  as  gravel  or  sheet  metal. 

Arrangement  of  Departments. — Departments  where  the  fire 
risk  is  greatest  should  be  divided  from  the  rest  by  fire  walls,  or 
placed  in  separate  buildings,  and,  as  far  as  possible,  floors  and 
departments  should  be  separated  from  each  other.  Openings 
through  the  floors  must  be  avoided,  for  they  not  only  allow  fire 
to  pass  up  through  the  building,  but  heat  from  fire  in  a  lower 


FIRE  PROTECTION 


321 


story  may  rise  through  floor  openings  and  cause  sprinklers  in 
upper  stories  to  open  with  accompanying  water  loss,  even  where 
fire  may  have  done  no  injury.  Stairs  between  the  floors  should 
be  in  separate  towers  outside  the  building  rectangle,  with  access 
to  them  through  automatic  closing  doors.  When  openings 
through  the  floors  are  unavoidable,  they  should  be  covered  with 
self-closing  hatches. 

Protective  Systems. — Automatic  sprinkling  systems  are  by  far 
the  best  fire  extinguishers,  for  not  less  than  70  per  cent,  of  all 
fires  in  buildings  so  equipped,  have  been  put  out.  Sprinklers  are 
of  two  kinds,  usually  known  as  (1)  the  wet  system,  and  (2)  the 
dry  system.  The  first  can  be  used  only 
where  pipes  will  not  freeze,'  while  the  sec- 
ond is  suitable  anywhere.  Small  water 
pipes  are  suspended  below  the  ceilings, 
with  sprinkler  nozzles  6  to  10  ft.  apart, 
the  nozzles  being  sealed  with  soft  metal 
which  melts  easily  at  a  temperature  of 
about  150  degrees,  or  about  50  degrees 
above  the  highest  summer  heat.  These 
pipes  are  connected  to  at  least  two  inde- 
pendent sources  of  water  supply,  usually 
the  public  system  of  the  city  and  a  private 
elevated  tank  or  stand  pipe.  Ceiling  pipes 
vary  in  size  from  f-in.  diameter  for  that 
which  supplies  a  single  head,  to  6-in.  dia- 
meter for  those  supplying  200  heads. 
Nozzles  (Fig.  163)  are  made  in  several 
ways  and  should  stand  above  the  pipe  in 

order  to  throw  water  on  the  ceiling  from  which  it  is  deflected  to 
the  floor.  This  not  only  gives  the  greatest  spread  of  water  but 
permits  the  pipes  to  be  drained,  all  those  on  the  ceiling  having 
a  slight  inclination  toward  the  vertical  ones.  Pipes  must  not 
be  enclosed  in  the  ceiling  or  in  casing,  but  must  be  open  for 
inspection. 

In  the  " dry  system"  where  water  in  the  pipes  would  freeze, 
water  is  held  back  by  compressed  air,  but  is  liberated  when  the 
sprinkler  fuses  melt. 

In  the  outside  system  of  yard  pipes  for  the   sprinklers   the 
supply  to  each  building  should  be  regulated  by  a  valve  outside 
the  building  which   can  be  closed  in  case  any  one  building  is 
21 


FIG.  163.— Sprinkler 
nozzel. 


322     ENGINEERING  OF  SHOPS  AND  FACTORIES 


destroyed,  for  if  such  pipes  were  left  open,  the  pressure  in  the 
other  buildings  would  be  lowered. 

Sprinkler  systems,  including  the  whole  equipment,  cost  6  to 
10  cents  per  square  foot  of  floor  area.     In  some  cases  the  inside 


FIG.  164.  FIG.  165. 

Hose  coils. 


FIG.  166. 


FIG.  167. 


Hose  coils. 


work  alone,  with  piping  and  heads,  has  cost  7  cents  per  square  foot, 

and  10  cents  per  foot  including  the  cost  of  tanks,  yard  pipes,  etc. 

Other  fire  fighting  appliances  include  sand  pails,  water  buckets, 

hose  coils  (Figs.  164-167)  and  chemical  extinguishers  (Fig.  168). 


FIRE  PROTECTION 


323 


These  are  useful  chiefly  for  putting  out  fire  in  its  first  stage 
before  the  sprinklers  have  begun  to  work.  Hose  pressures 
should  not  exceed  40  to  60  Ib.  per  square  inch,  for  those  who 
are  not  accustomed  to  handling  hose  are  unable  to  control  the 
nozzle  at  high  pressures.  The  discharge  of  water  through 
nozzles  of  different  size  at  a  pressure  of  100  Ib.  per  square  inch 
is  as  follows : 


FIG.  168. — Chemical  extinguisher. 

1  |  in.  nozzle,  discharges  at  100  Ib.,  466  gallons  per  minute. 
1  \  in.  nozzle,  discharges  at  100  Ib.,  671  gallons  per  minute. 

1  £  in.  nozzle,  discharges  at  100  Ib.,  904  gallons  per  minute. 

2  in.  nozzle,  discharges  at  100  Ib.,  1194  gallons  per  minute. 

Inspection. — Rigid  and  frequent  inspection  of  plants  by  officers 
of  the  Fire  Insurance  Companies  is  one  of  the  best  methods  of 
preventing  fire  loss.  These  inspections  are  made  every  three 
months  by  different  men  who  are  not  supplied  with  previous 
reports,  and  independent  inspections  of  this  kind  are  therefore 
a  check  on  each  other.  Examination  is  made  of  every  thing 
pertaining  to  fire  risk,  including  the  methods  of  lighting,  heating, 


324     ENGINEERING  OF  SHOPS  AND  FACTORIES 

type  of  construction,  building  contents  and  appliances,  nearness 
of  fire  hydrants  and  the  local  protective  system.  The  degree  of 
order  and  cleanliness  maintained  inside  the  building,  and  the 
familiarity  of  the  occupants  with  the  methods  provided  for  fire 
extinction,  are  all  noted  and  reported.  Such  inspections  are,  of 
course,  quite  expensive,  but  have  proved  to  be  ultimate  economy. 
While  inspection  by  officers  of  the  insurance  companies  is 
valuable,  it  should  not  be  left  wholly  to  them,  because  their 
examinations  are  frequently  more  for  their  own  benefit  than  for 
the  owners  or  occupants.  The  insurance  co'mpany  may  be 
willing  to  receive  a  higher  rate,  and  are  often  most  interested  in 
seeing  that  the  rate  is  high  enough. 

Cleanliness  and  Order. — Prevention  of  fire  is  better  than 
extinction,  for  loss  is  rarely  covered  by  the  insurance.  Failure 
to  complete  contracts  on  time,  the  scattering  of  workmen  and 
loss  of  business,  are  matters  not  in  the  insurance  policies.  It  is 
therefore  wisdom  to  use  every  effort  toward  the  prevention  of 
fire,  and  no  measures  are  more  effective  in  this  direction  than 
order  and  cleanliness.  Certain  rules  should  be  established  in 
reference  to  smoking  or  the  use  of  fire  about  the  buildings,  and 
violations  of  these  rules  should  be  punished  by  suspension  or 
dismissal. 

Buildings  should  be  cleaned  daily  during  daylight,  preferably 
just  before  closing.  This  will  not  only  avoid  the  need  of  artificial 
light  and  its  accompanying  danger,  but  will  give  janitors  better 
light  for  their  work,  and  avoid  any  excuse  for  improper  service. 
Aisles  will  no  doubt  be  kept  clean,  and  attention  should  be  given 
to  space  under  tables,  behind  machines,  in  closets,  or  under 
stairs,  where  dirt  is  most  likely  to  accumulate.  Rubbish  must 
not  be  allowed  to  collect,  but  must  be  removed  from  the  shops 
to  outer  sheds  or  to  the  dump.  Rubbish  boxes  should  be 
of  metal  with  self-closing  covers,  and  they  should  be  emptied 
daily. 

Dust  is  a  common  cause  of  fire,  and  once  or  twice  a  month, 
the  whole  building  interior  should  be  swept  and  dust  removed 
from  such  places  as  door  and  window  heads,  and  from  the  truss 
framing  if  it  is  exposed.  Certain  articles  used  about  shops  often 
cause  spontaneous  combustion.  Dust,  shop  sweepings,  or  waste 
when  soaked  with  oil  frequently  take  fire,  and  sal  ammoniac  and 
iron  filings  mixed  with  dirt  are  also  dangerous,  and  these  should 
not  be  permitted  to  collect  or  remain  unprotected.  Likewise 


FIRE  PROTECTION 


325 


the  dust  from  grinding  stones  and  emery  wheels  settling  on  wet 
surfaces  is  likely  to  take  fire.  Cellars,  attics  and  all  hidden 
places  should  be  kept  clean  and  clear  of  rubbish,  and  the  pre- 
vention of  fire  should  be  included  as  part  of  the  regular  expense. 

Employees  in  pattern  and  templet  shops  have  occasionally 
been  found  drying  lumber  over  furnaces,  or  using  other  dangerous 
means  to  hasten  the  seasoning,  and  at  other  times,  torches  arid 
gasoline  lamps  have  been  carelessly  used.  Any  such  careless 
conduct  should  be  effectively  stopped  and  its  repetition 
prevented. 

Fire  Drill. — A  regular  system  of  fire  drill 
should  be  maintained  at  every  factory. 
These  systems  should  be  governed  by  law 
and  should  be  uniform  for  all  plants,  so 
that  employees  changing  from  one  place  to 
another  will  not  be  obliged  to  learn  a  new 
lot  of  regulations,  or  be  confused  with 
orders  with  which  they  are  not  familiar. 
The  system  of  drill  should  be  military  in 
character,  under  the  direction  of  officers 
of  different  rank.  It  should  be  directed 
by  a  fire  marshall  whose  authority  in  these 
matters  is  supreme,  and  captains  should 
have  charge  of  floors  or  buildings,  with 
lieutenants  for  separate  rooms.  The  or- 
ganization should  be  extended  further  if 
necessary,  with  foremen  to  direct  the 
movements  of  occupants  in  companies  of 
twenty-five  to  fifty  persons.  All  officers 
should  be  accustomed  to  command,  so  their 
authority  in  fire  emergencies  will  be  re- 
spected. Other  men  will  be  assigned  to 


FIG.  169.— Hand  ex- 
tinguisher. 


special  duties  as  required,  and  to  prevent  crowding,  stairs  and  fire 
escapes  should  have  a  guard  at  every  landing.  The  officers 
should  make  daily  or  frequent  inspections,  noting  stairs,  exits 
and  passage  ways  to  see  that  they  are  ahvays  clear.  Doors 
must  always  open  outward  and  must  be  examined  to  see  that 
those  at  exits  which  are  seldom  used  excepting  at  fire  drill,  are 
accessible.  Gongs  or  other  signals  must  be  kept  in  order. 

Full  printed  instructions  for  fire  drill  and  protection  must  be 
posted  conspicuously  throughout  the  buildings,  and  in  different 


326     ENGINEERING  OF  SHOPS  AND  FACTORIES 

languages,  if  necessary.  Orders  should  be  announced  by  bells  or 
gongs  in  the  different  stories  under  the  direction  of  the  captains, 
who  receive  their  orders  from  the  marshall  on  an  outer  gong  of 
different  tone.  Fire  is  first  announced  by  a  succession  of  strokes 
on  the  marshail's  gong,  and  immediately  all  occupants  of  the 
building  should  come  ta  attention,  shut  off  power  from  their 
machines,  and  stop  work.  Successive  orders  from  the  floor 
captains  may  be  given  as  follows: 

One  stroke  of  gong,  meaning  to  clear  the  passage  w^ys. 

Two  strokes  of  gong,  meaning  to  form  in  line. 

Three  strokes  of  gong,  meaning  to  march  out  of  the  building. 

These  drills  should  be  given  at  least  once  a  fortnight  at  irregular 
intervals  without  previous  announcement,  and  all  occupants  of 
the  building  must  take  part.  The  regular  entrances  with  which 
employees  are  most  familiar  should,  as  far  as  possible,  be  used  in 
preference  to  any  others.  If  there  are  insufficient  exits  or 
dangerous  defects  in  the  protective  system,  they  will  be  disclosed 
by  these  drills  and  may  then  be  remedied. 

All  exits  must  be  indicated  by  red  lights.  Fire  officers  should 
keep  with  them  a  pocket  memoranda  with  the  names  of  all  occu- 
pants of  their  respective  rooms  or  departments,  and  after  each 
drill,  names  should  be  announced  and  checked  off  on  the  list, 
to  see  that  all  are  accounted  for.  Before  marching  from  the 
building,  all  lights  should  be  extinguished. 

In  case  of  fire,  hand  extinguishers  (Fig.  169)  should  be  used 
to  the  limit  of  their  usefulness  before  resorting  to  other  methods. 
When  passing  through  dense  smoke,  a  wet  handkerchief,  cloth, 
or  waste,  should  be  tied  over  the  mouth  and  nose,  and  as  smoke 
rises  and  has  the  least  density  at  its  lowest  level,  escape  in  extreme 
cases  may  be  made  by  crawling  along  the  floor. 


CHAPTER  XXVII 
CRANES 

Hand  Traveling  Shop  Crane. — The  accompanying  illustration 
(Fig.  170)  shows  a  typical  shop  crane,  designed  by  the  writer, 
in  a  series  of  dimensions  and  capacities,  several  of  which  have 
been  built  and  put  into  successful  operation.  The  principal 


I 


,%'  Chain 


Section 


FIG.  170. — Shop  crane. 

feature  of  the  design  is,  that  it  gives  the  greatest  amount  of  lift 
or  clearance  beneath  the  bridge,  and  leaves  space  for  knee  braces 
in  the  building  frame.  In  steel  frame  buildings  with  traveling 
cranes  of  the  usual  type,  vertical  space  is  lost  by  keeping  the 
crane  low  enough  to  clear  the  knee  braces.  If  such  clearance  is 

327 


328     ENGINEERING  OF  SHOPS  AND  FACTORIES 

not  provided,  and  knee  braces  are  omitted  or  made  so  small  that 
they  are  almost  useless,  the  stiffness  of  the  whole  frame  is 
sacrificed.  In  this  design,  however,  ample  room  is  left  for  deep 
braces,  and  the  crane  bridge  is  placed  close  up  under  the  roof 
trusses',  resulting  in  a  stiff  building  frame  and  maximum  clearance 
under  the  crane. 

Another  important  feature  of  ttr6  design  is  the  side  or  lateral 
bracing.  It  is  important  that  a  shop  crane  should  travel  truly 
parallel  with  the  building.  But  with  insufficient  bracing  the 
frame  of  the  crane  is  liable  to  get  out  of  square,  Causing  one  end 
to  travel  slightly  in  advance  of  the  other.  To  prevent  such 
action  this  crane  has  wide  side  bracing  connecting  out  to  the 
extremities  of  the  end  trucks. 

As  previously  stated,  these  cranes  are  made  of  various  sizes 
and  capacities,  but  the  standard  form  of  specification  is  as 
follows: 

SPECIFICATION  FOR  HAND  TRAVELING  CRANE. 

General. — The  crane  will  be  as  shown  on  the  print  accompany- 
ing these  specifications.  It  consists  of  a  box  girder  grooved  on  the 
upper  side,  and  mounted  at  the  ends  on  a  pair  of  trucks  which 
are  carried  on  24-in.  cast-iron  chilled  tread  wheels.  The  wheels 
are  ground  to  run  on  standard Ib.  track  rails. 

The  gearing  throughout  is  steel  spur  gears,  with  teeth  cut 
from  the  solid.  The  end  truck  wheels  have  roller  bearings. 
The  general  dimensions  are  as  shown  on  the  plan. 

Capacity. — The  lifting  capacity  of  the  crane  is tons, 

and  the  guaranteed  testing  capacity tons.  The 

height  of  lift  is ft. 

Movement. — The  bridge  travel  is  operated  with  a  hand  chain 
working  on  a  36-in.  sprocket  wheel,  which  is  geared  through  a 
series  of  reduction  gears  to  one  pair  of  truck  axles.  The  shaft 
to  which  this  sprocket  is  geared  runs  along  the  length  of  the 
crane  and  is  supported  at  intermediate  points  to  the  frame. 

The  trolley  is  moved  by  pulling  on  the  suspended  hoisting 
block. 

The  lifting  is  performed  by  pulling  on  the  3/8-in.  chain  of  a 

ton  triplex  hoisting  block,  which  is  part  of  the  block 

mechanism. 

Trolley. — The  trolley  is  made  of  four  single  flange in. 


CRANES  329 

chilled  tread  wheels  supported  by  bent  plates  that  are  curved  in 
at  the  lower  side  and  united  with  a  pin  on  which  the  hoist  block 
is  sustained.  The  trolley  wheels  run  in  the  outer  faces  of 
channels  which  form  the  lower  chord  of  the  crane  girder. 

Hoist  Block  and  Hook. — The  hoist  block  is  forged  from  the 
best  refined  iron,  and  is  amply  strong  enough  to  carry  its  maxi- 
mum load.  It  swivels  on  hardened  steel  balls  turning  between 
disks. 

Material. — The  material  of  the  bridge  and  other  riveted  parts 
is  medium  open  hearth  or  Bessemer  steel  with  an  ultimate 
capacity  of  50,000  to  60,000  Ib.  per  square  inch  in  tension.  The 
maximum  fiber  stresses  used  in  proportioning  the  crane  are 
10,000  Ib.  per  square  inch  in  compression,  and  12,000  Ib.  per 
square  inch  in  tension.  A  factor  of  safety  of  five  is  provided 
throughout. 

Wheel  Loads. — The  maximum  wheel  load  is Ib.,  or 

a  total  of Ib.  on  the  two  wheels  at  the  loaded  end  of 

the  crane.  This  weight  includes  the  weight  of  the  frame, 
machinery  trolley,  hoist  block  and  suspended  load. 

Erection. — The  crane  is  to  be  erected  by  the  contractor,  so  he 
shall  be  responsible  for  the  proper  and  efficient  working  of  the 
machine. 

Guarantee. — The  contractor  guarantees  the  crane  to  be  made 
of  the  best  material,  and  to  be  satisfactory  and  according  to 
specifications  in  every  respect.  Any  breakage  that  may  occur 
within  one  year  after  date  of  contract  or  purchase,  will  be 
replaced  by  the  contractor  free  of  charge  to  the  purchaser.  It 
is  guaranteed  also  to  handle  the  working  load  with  ease  and 
safety. 

NOTE. — The  subject  of  "Cranes"  is  so  extensive  that  it  is  impossible  to 
give  it  any  comprehensive  treatment  in  the  scope  of  this  volume.  Several 
treatises  have  been  written  covering  all  branches  of  the  subject,  and  to 
these  the  reader  is  referred  for  fuller  information.  Weight  tables  for  hand 
and  power  cranes  may  be  found  in  Tyrrell's  "Mill  Buildings/'  and  in  a 
later  edition  of  this  book  it  is  hoped  to  give  the  subject  greater  considera- 
tion. Mention  is  made  here  only  to  the  writer's  design  for  a  simple  form  of 
hand  crane  which  can  easily  be  made  in  any  structural  shop. — THE  AUTHOR. 


CHAPTER  XXVIII 
YARDS  AND  TRANSPORTATION 

The  arrangement  of  buildings  in  relation  to  each  other,  with 
their  storage  and  shipping  facilities,  is  discussed  to  some  extent 
in  Chapter  II,  but  further  particulars  of  the  yards,and  the  means 
of  transferring  materials  between  the  buildings  is  given  here. 


FIG.  171. — Hicks  Locomotive  and  Car  Works,  Chicago  Heights. 

Only  small  shops  with  light  products  can  carry  on  business 
economically  without  a  railroad  connection,  for  the  receiving 
and  unloading  of  fuel  is  reason  enough  for  the  presence  of  a 

330 


YARDS  AND  TRANSPORTATION  331 

siding.  The  shipping  of  even  one  carload  per  week  might  very 
soon  pay  for  track  facilities  or  for  a  better  location. 

The  laying  out  of  yards  (Fig.  171)  includes  grading,  placing  of 
sewers,  water  pipes,  tracks,  switches,  engine  or  motor  sheds, 
trolley  lines,  scale  and  weighing  house,  driveways,  footwalks, 
fences,  gates,  etc.  Some  of  these  items,  especially  the  arrange- 
ment f  of  tracks,  is  of  vital  importance  to  the  interest  of  the 
business. 

Track  Arrangement. — Tracks  in  manufacturing  yards  are  of 
two  kinds,  (1)  standard  gauge  for  heavy  cars,  and  (2)  light  ones 
for  hand  cars  and  trucks.  Enough  of  the  former  kind  must  be 
used  to  ship  and  store  heavy  goods,  and  as  many  of  the  lighter 
ones  for  moving  smaller  parts  as  convenience  may  direct.  The 
arrangement  of  tracks  will  depend  to  some  extent  on  the  kind  of 
power  and  type  of  motors,  though  connection  to  the  main  line  of 
railway  will  always  be  with  standard  gauge.  Yard  tracks  may  be 
laid  out  in  either  one  of  two  ways,  (1)  with  stub  end  sidings 
(Fig.  172),  and  (2)  with  a  circuit  or  loop  (Fig.  173).  The  first 
method  is  sufficient  for  small  plants,  and  may  sometimes  be  for 
larger  ones  if  enough  sidings  are  provided,  though  in  large  works 
the  loop  or  circuit  system  has  the  greatest  advantage.  Circuits 
should  have  two  connections  to  the  main  line  and  should  have  all 
the  additional  sidings  that  will  ever  be  needed  for  the  storage  of 
cars,  the  sidings  running  off  by  a  system  of  yard  "ladders." 
Turntables  for  turning  cars  are  usually  a  nuisance  for  they  be- 
come clogged  with  snow  and  ice  and  leave  a  partially  open  and 
dangerous  pit.  Curves  are  much  better,  and  those  for  standard 
gauge  should  have  a  radius  of  235  ft.  or  more,  so  cars  arid  locomo- 
tives will  not  bind,  while  the  radius  for  30-in.  gauge  should  not  be 
less  than  40  ft. 

The  need  of  running  wide  gauge  tracks  into  the  buildings  will- 
depend  on  conditions  and  the  methods  of  receiving  and  shipping 
as  previously  determined.  Heavy  goods  such  as  structural  work 
and  machinery,  which  is  completed  in  the  shop  ready  for  ship- 
ment, may  be  loaded  by  running  cars  into  the  building  or  by 
extending  the  shop  cranes  out  through  the  end  and  over  the  ship- 
'ping  yards.  In  the  former  case,  with  cars  admitted  to  the  shop 
for  loading,  it  is  usually  sufficient  to  project  the  tracks  one  or  two 
car  lengths  into  the  shop  on  a  stub,  and  after  loading  the  car,  to 
withdraw  it  again.  The  cost  of  standard  gauge  with  rails  and 


332     ENGINEERING  OF  SHOPS  AND  FACTORIES 


••  •==L-- 


YARDS  AND  TRANSPORTATION 


333 


ties  may  be  estimated  approximately  at  the  rate  of  $2  per  lineal 
foot. 

Light  track  for  service  cars  should  be  freely  used  about  the 
yard  and  works,  but  adjoining  ones  should  not  be  closer  together 
than  6  ft.  on  centers.  The  distance  between  rails  may  vary 
anywhere  from  15  in.  to  4  ft.  8  1/2  in.  as  used  for  standard  steam 
cars,  though  the  usual  width  is  30  in.  Rails  weighing  40  Ib.  per 
yard  are  heavy  enough,  and  in  shops,  streets  or  thoroughfares, 
the  rail  heads  should  never  be  above  the  floor  or  grade.  Drive- 
ways about  the  yard  or  between  the  tracks  and  buildings  may 
conveniently  be  paved  with  brick,  which  is  easier  to  walk  upon 
than  stone,  and  offers  a  better  foothold  for  horses  than  asphalt. 


FIG.  173. — Canadian  Pacific  Railway  shops.     Montreal,  Canada. 

Motors. — The  kinds  of  haulage  motor  used  about  shops  and 
industrial  works  include  steam,  electric  and  compressed  air  loco- 
motives, the  electric  type,  all  things  considered,  being  the  best. 
These  can  travel  on  the  standard  gauge  steam  tracks,  even  though 
the  custom  is  not  favored  by  the  steam  railroad  officials.  When 
the  trolley  wire  for  an  electric  locomotive  would  interfere  with 
the  movement  of  cranes,  the  locomotive  can  have  a  trolley 
connection  through  a  slot  in  the  floor,  or  when  entering  a  building 
with  the  trolley  on  an  overhead  wire,  the  wire  can  be  made  to 
uncoil  in  advance  of  the  locomotive  and  furnish  it  with  power, 
the  wire  coiling  up  again  as  the  motor  recedes.  A  motor  derrick 
car  is  also  very  handy  about  the  yard  for  lifting  and  loading  goods. 

Compressed  air  locomotives  are  perhaps  the  safest  about  works 
which  have  much  lumber  or  other  combustible  materials,  but  as 
they  require  a  higher  air  pressure  than  used  for  other  purposes, 
an  additional  heavy  and  expensive  compressor  is  needed.  With 
any  of  the  above  kinds  of  motor  haulage,  small  industrial  cars 


334     ENGINEERING  OF  SHOPS  AND  FACTORIES 

must  be  supplied  for  the  service  tracks,  and  hand  trucks  with 
slightly  rounded  tires,  preferably  covered  with  rubber,  are  useful 
for  moving  goods  promiscuously  about  the  shops  to  parts  not 
served  by  the  narrow  gauge  tracks.  Car-wheel  treads  should  not 
be  flat,  but  slightly  tapered  inward  toward  the  flange  as  on 
standard  heavy  cars. 

Loading  and  Conveying  Apparatus. — Lifting  and  handling- 
appliances  about  the  yards  and  buildings,  include  traveling  cranes, 
gantry  cranes,  trolleys,  mono-rails,  transfer  tables,  and  moving 
platforms.  Nearly  all  modern  plants  are  equipped  more  or  less 
with  traveling  cranes,  and  in  metal  working  shops  and  power 
houses  they  are  an  economic  necessity.  Many  works  now  have 
their  whole  yards  covered  by  a  system  of  traveling  cranes  on 


3&&±'<>     a  ve  *•*<-<- 


FIG.  174. — Cantilever  crane. 


elevated  tracks.  When  the  cranes  move  between  adjoining- 
buildings  with  girders  on  the  wall  columns,  the  supports  then 
form  no  additional  obstructions,  but  over  larger  yards  where 
special  runways  must  be  erected,  this  type  of  crane  is  not  so 
desirable.  In  such  cases  traveling  gantry  cranes  are  better. 
Cantilever  gantries  with  a  central  tower  moving  on  a  pair  of 
tracks,  and  arms  overhanging  the  yard  at  each  side  (Fig.  174), 
offer  the  least  obstruction  but  are  not  so  stable  as  those  with  end 
supports,  though  some  makes  give  excellent  results. 

Individual  trolleys  are  suitable  for  lifting  and  conveying  loads 
up  to  5  or  6  tons  in  weight  or  occasionally  up  to  10  tons,  and  they 
have  the  merit  of  comparatively  low  cost  but  they  can  travel  only 
in  one  general  direction  without  lateral  movement. 

Mono-rail  systems  which  are  only  a*  special  kind  of  trolley 
conveyor  are  useful  in  connection  with  traveling  cranes  and  can 


YARDS  AND  TRANSPORTATION  335 

be  provided  with  switches  and  cross-overs  or  can  travel  around 
curves  and  corners.  The  trolley  support  consists  of  a  single  bar 
of  wrought  metal  folded  over  in  such  shape  that  the  trolley  runs 
within  it,  and  the  thickness  of  the  metal  is  proportioned  to  the 
load  to  be  sustained.  The  track  is  in  many  respects  similar  to  a 
familiar  type  commonly  used  for  rolling  doors.  Its  narrow 
width  and  light  metal  permits  it  to  be  curved  to  comparatively 
small  radii  for  turning  corners.  This  system  is  extensively  used 
in  multi-story  buildings,  especially  in  packing  plants,  where  the 
tracks  have  connections  with  the  freight  elevators  for  transferring 
goods  to  any  story. 


CHAPTER  XXIX 
ESTIMATING 

In  order  to  illustrate  methods  of  estimating  building  costs, 
examples  are  given  of  estimates  and  bids  made  by  the  writer  in 
1908,  for  two  different  manufacturing  plants. 

The  first  of  these  is  for  the  superstructure  of  three  metal 
working  shops  at  Chicago  containing: 


1  Building,  125X175  ft. 
1  Building,  16X133  ft. 
1  Building,  112X230  ft. 


1  Story     and  basement,    Bldg.  A. 

2  Stories  and  basement,    Bldg.  B. 
2  Stories  and  basement,    Bldg.    C. 


Building  A. 


Number  of  square  feet  of 
wall  of  different  thicknesses 
12  in.    16  in.     21  in.  24  in. 


Brick.     Front, 


East, 


West, 


Rear, 
Inside  wall, 


1  Stack, 
1  Stack, 


16  in.  wall     5^X175  ft., 

1,750 

16  in.  wall     4^X175  ft., 

12  piers          22X2X4  ft., 

1,056 

16  in.  wall     5|Xl25ft., 

1,125 

16  in.  wall     3$  X  125  ft., 

4  piers     15  ft.  X21  in.  X4  ft. 

440 

Spiers     10  ft.  X  21  in.  X  4  ft., 

16  in.  wall     5|Xl25ft., 

16  in.  wall       6X125  ft., 

1,437 

4  piers            2X4X19  ft., 

304 

4  piers            2X4X10  ft., 

160 

16  in.  wall     12X175  ft., 

2,100 

12  piers            2X4X11  ft., 

528 

80  X  10  ft.  X  17  in., 

800 

175  X  10  ft.  X  17  in., 

1,750 

80  X  18  ft.  X  12  in.,                       1,440 

30  X  10  ft.  X  12  in.,                        300 

175  X  30  ft.  X  12  in.,                    5,250 

16X40  ft.Xl7  in., 

640 

20X40ft.Xl7in., 

800 

6,990  10,402  440   2,048 


336 


ESTIMATING 

Face  brick,  deduct  from  above  at  $16.00  per  M. 

32X220  ft.,  7,040 

Less  12X19X14  ft. 

12X  4Xl4ft. 
24X16  ft.,  384 

15X9  ft., 
20X50  ft.,  1,000 

12X11X3  ft., 


8,424 


Tile  wall  capping,  435  lin.  ft. 

Fire  brick,  4  in.  thick  22X40  ft.  800  sq.  ft. 


337 


3,192 
672 

135 
396 

4,395    =   4,029  sq.ft. 
=  28,200  brick 


=   6,160  brick 


Summary. 


6,990  sq.  ft.  wall,    12  in.  thick,  at  20  bricks,  139,800 

10,402  sq.  ft.  wall,     16  in.  thick,  at  26  bricks,  270,452 

2,488  sq.  ft.  wall,    21  in.  thick,  at  34  bricks,     82,104 


Building  B. 


492,356  less 
28,000  face  =  464,000  bricks. 


Brick.     2  Walls  12  in.  thick,  35X133  ft. 

Less       9     4X2Jft.  90 

13     4X9  ft.,  468 

8     4X6  ft.,  192 

5     6X13  ft.,  390 


9,310 


Brick  face     say  16  in.  thick, 
7X120  ft. 


Tile  Coping     130  ft.  for  12  in.  wall. 
Face  brick  40  M  (deduct  from  above). 
22 


1,140 

8,170X20=  163,400 
21,800 

185,200 


338     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Building  C. 

Brick. 

12-in.  face  wall,  684X34  ft. 

50  Pilasters     2$  ft.  X8  in.  X30 

Less  64     11X8  ft.,  5,632  sq.  ft. 

32     11X3  ft.,  1,056 

32     10X9  ft.,  2,rf§80 

16     10X2  ft.,  '320 


23,256 


12-in.  inside  wall  124X42  ft. 
40X42  ft. 
50X42  ft., 
24X42  ft. 
16X52  ft., 


400  ft.  tile  wall  coping  12-in.     wall. 
Firebrick    4  in.  thick,    20X50  ft. 
Face  brick    434  X  34  ft.  =  15,436 

Less  64    8X11  ft.  5,760 


9,888 

a3,368 sq.ft.  net 
9,996 
832 


24,196 


9,676  X  7  =68  M.     Deduct  from  above. 


Summary. 


12-in.  wall    24,200  sq.  ft.  at  20, 
8-in.  wall      3,750  sq.  ft.  at  14 


484,000 
52,500 

536,500 


Brick  summary. 

Building  A., 
Building  B., 
Building  C., 


Common 

Face 

Fire    Tile  coping 

464,000 

28,000 

6,160     435  lin.  ft. 

145,000 

40,000 

130  lin.  ft. 

468,000 

68,000 

7,000     400  lin.  ft. 

1,077,000        136,000          13,160     965  lin.  ft. 


Building  A. 
Stone. 


2  stone  chimney  caps,    5X5  ft.      50  sq.  ft. 
1  stone  chimney  cap,      3X3  ft.,       9  sq.  ft. 
Coping  10  in.  X2£  ft.,  415  lin.  ft.  830  sq.  ft. 
300  lin.  ft.  stone  belt  course  5X8  in. 

21  window  sills      5X8  in.  X12  ft.  long. 


ESTIMATING 


339 


Building  B. 


Stone. 


110-ft.  coping    10  in.  X2  ft.  0  in. 

130-ft.  coping    10  in.  X2  ft.  2  in. 

6  stone  gate  posts  3£X3JX10  ft.  =735  cu.  ft. 

62  stone  sills      5ft.  0  in. 


Building  C. 
Stone. 


464-ft.  wall  coping,  10  in.  X2  ft.  0  in. 

96  stone  sills,  10  ft.  long. 

Entrance  Ashlar,  220  sq.  ft. 


Summary  of  stone. 


1119-ft.  coping,       10  in.  X  2  ft.  5  in. 

=  2,220  cu.  ft.  at  $1.20 

$2,660 

1822-ft.  sill,        5X8  in., 

=    600  cu.  ft.  at      .60 

1,092 

2  chimney  caps,     5X5  ft., 

=      50  cu.  ft.  at    2.00 

100 

1  chimney  cap,      3X3  ft., 

=        9  cu.  ft.  at    2.00 

18 

6  gate  posts,      3£  X  3  J  X  10  ft., 

=    735  cu.  ft.  at    1.20 

882 

Entrance  Ashlar, 

220  sq.  ft.  at      .60 

132 

Setting, 

3,724  cu.  ft.  at      .30 

1,117 

$6,001 


Building  A. 

Tile  partitions. 

61  X 16  ft.  of  6-in.  tile,  976 
36  X 10  ft.  of  6  in.  tile,  360 

1,336 
60X16  ft.  of  8  in.  tile,  =960 


Building  C. 

Tile. 

Second  story,  180  ft.,  double  6  in.  tile  wall,  18  ft.  high,  6,480  sq.  ft. 

Second  story,  58  ft.,  single  6  in.  tile  wall,  14  ft.  high,  812  sq.  ft. 

First  story,  180  ft.,  double  6  in.  tile  wall,  15  ft.  high,  5,400  sq.  ft. 

First  story,  124  ft.,  single  6  in.  tile  wall,  15  ft.  high,  1,860  sq.  ft. 

Basement,  161  ft.,  double  6  in.  tile  wall,    9  ft.  high,  2,898  sq.  ft. 


17,450  sq.  ft. 


340     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Summary  of  Tile. 

6  in.  18,790  sq.  ft. 
8  in.        960  sq.  ft. 

Building  A. 

Concrete.  *-.  .  ^ 

Cellar  paving  6  in.  thick  1  ft.  =21,875  sq.  ft. 

With  expanded  metal  4  in.  No.  10  J 
Granolithic  surface  1  1/4  in.  thick,  125X175  ft. 

it 

Building  A. 

Reinforced  Concrete.     Design  by  Contractor. 

(16X30  ft.  480 

13X36  ft.  468 

16X78  ft.  1,248 


Building  B. 


2,196 

Floor,     78  ft.  X 110  ft.  cellar       8,580 
Granolithic  surfaces  on  78X110  ft. 


Concrete  paving  similar  to  A. 
16X133  ft.  =2,128 


Building  C. 

Reinforced  concrete. 

10-24X13  ft.=3,120 
1-   8X  8ft.-      64 
Cellar  pavement,  112X230  ft.  1  7i  in.  thick  with  Ex.  met.  4  in. 

}  No.  10  D. 

Area,  3  X230  ft.  J  26,450  sq.  ft. 

Over  vault,  12X12X2  ft.  =  288 
Press  pit  900  sq.  ft.     3  in.  on  Ex.  metal. 
Plain  concrete. 

Area  wall  230-3 XI J  ft.  1,035  cu.  ft.  =40  cu.yd. 

Summary  of  concrete. 

Cellar  floor  and  surface 

with  ex.  metal  Roof  Floor 

Bldg.  A,  21,875  2,200  8,580 

Bldg.  B,  2,130 

Bldg.  C,  26,450  3,184  288 

50,455  sq.  ft.  5,384  sq.  ft.    8,868  sq.  ft. 


ESTIMATING 

Cellar  floor,    50,455  sq.  ft.  =5,606  sq.  yd.  at  18=  8,658 

Roof,                 5,384  sq.  ft.  at  25  =1,346 

Second  floor,    8,868  sq.  ft.  2,474 

3  in.  wall,             900  sq.  ft.  135 

Area  wall,       40  cu.  yd.  200 


341 


Building  A. 


4,155 


12,813 


Carpentry. 

No.  1,  L.  L. 

y.  p.  s.  3.  s. 

9 

6X12  in. 

175  ft. 

9,450 

17 

6X12  in. 

64  ft. 

6,528 

55 

2X10  in. 

80  ft. 

7,333 

37 

10X12  in. 

65  ft. 

24,050 

11 

8X14  in. 

14  ft. 

1,440 

26 

6X14  in. 

14   ft. 

2,600 

58 

10X14  in. 

30  ft. 

20,300 

71,701  ft.  B.  M. 


Sheathing. 

Roof, 

Second, 

First, 


Maple  flooring, 
7,350  sq.  ft. 
No.  1  maple  in  office 


If  X  6  in.  125X175  ft.  matched  y.  p.  21,875 
2|  X  6  in.  80  X  1  10  ft.  matched  y.p.  8,800 
2f  X  6  in.  42  X  175  ft.  matched  y.p.  7,350 


in.  X  175X42  ft.   matched  side  and  end 


j.i  \j.  J.  juiapic  ui  uiuue 

Building  paper,  175X42  =  7,350  sq.  ft. 


Erect  mill  work. 
Erect  hardware. 

Coal  bunkers,  48  ft.  long  X  9  ft.  high. 

20     4X   6  in.  X9  ft.,  360 

6     6X10  in.  X9ft.,  270 

2  in.  plank,  48X9  ft.,      960 

150ft.     6X8  in.,  600 


2,190  ft.  B.  M. 


342     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Weights  and  cords. 
Building  B. 

Carpentry. 

53- 

8X14 

in. 

X   18 

ft.= 

45- 

7X14 

in. 

X   18 

to- 

23- 

6X12 

in. 

X   18 

ft. 

2- 

8X12 

in. 

X   90 

ft. 

1- 

8X12 

in. 

X132 

ft. 

2- 

8X14 

in. 

X   90 

ft. 

1- 

8X14 

in. 

X120 

ft. 

2- 

4X   8 

in. 

X133 

ft. 

2_ 

7X14 

in. 

X   44 

ft. 

1- 

10X12 

in. 

X   44 

ft. 

8,904 

6,615 

2,484 

1,440 

1,064 

1,680 

1,120 

704 

735 

440 


{6  in.  floor,  8X278  ft.     1 
6X3  in.  on  edge 
with  f  in.  open  joint      J 
2f  in.  flooring,  First  floor, 

second  floor, 
If  in.  flooring,   roof, 


25,186 
12,000 


16X133  ft.  =  2,000  sq.  ft. 

16X133  ft.  =2,000  sq.  ft. 

16X133  ft.  =2,000  sq.  ft. 
H  in.  finish  flooring,  first  floor,   16X133X2.     Maple  =  4,000  sq. 

ft.  net. 

Building  paper,  16X133X2  ft.  =4,000  sq.  ft,/ 
Weights  and  cords  for  all  3  buildings.  *- 

Weights  460  windows  at  60  lb.,  27,600  lb.,  say  15  tons 

at  $30  =  $450 
Cords,      460  windows  at  20  ft.     9,200  ft.  at  .04,  350 


$800 


Building  C. 

Carpentry. 


Roof, 

Second, 

First. 


50-   6X12  in. 

112  ft. 

33,600 

66-    8X12  in. 

109  ft. 

5     7,550 

12-10X14  in. 

68  ft. 

9,520 

44  -10X14  in. 

42ft. 

21,560 

36-    6X14  in. 

42ft. 

10,504 

54-12X16  in. 

27  ft. 

23,328 

16-  10X14  in. 

54ft. 

10,080 

20-    6X14  in. 

56ft. 

7,840 

173,982 


ESTIMATING 


343 


Flooring  and  Roofing. 

If  Roof 
Less  10 


109X227  ft. 
13X24    ft. 


2|  in.  flooring  second,  109X227  ft. 
Less  4  10X20    ft. 


First, 
Less  4 


109X227  ft. 
10X20    ft. 


=  24,743  sq.  ft. 
3,120 

21,623 

24,734 

800 


23,943 

24,743 

800 

23,943 


1J  in.  maple,  first  and  second  floors,     24,000X2  sq.  ft.  =48,000  sq.  ft. 

Building  paper,     48,000  sq.  ft. 
Wood  bolts,  spikes,  nails,  etc.     Total  lumber  624,000  ft.  B.  M. 


Floor  Anchors. 


Using  10  Ib.  for  1,000  ft.  B.  M.  framing  timbers. 
Using  30  Ib.  for  1,000  ft.  B.  M.  flooring. 

285  M  framing  at  10  Ib.  nails  per  M=   2,850  Ib. 

400  M  flooring  at  30  Ib.  nails  per  M  =  12,000  Ib. 


14,850  =  148  kegs 
Or,  if  one  keg  used  for  every  3,000  ft.  B.  M. 

No.  kegs  =>  =  228  kegs. 


Carpentry  Summary. 


Framing 
timber 

If  X6 

2|X6 

Maple 

Paper 

3X6  in. 

Building  A  
Building  B  
Building  C  

73,890 
25,186 
173,982 

21,875 
2,000 
21,623 

16,150 
4,000 
48,000 

7,350 
4,000 
48,000 

7,350 
4,000 
48,000 

12,000 

273,058 

45,498 

68,150 

59,350 

59,350 

12,000 

344     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Carpentry  Summary,  continued. 


Framing  timber, 
Flooring,  If  X6, 
Flooring,  2f  X  6, 
Flooring,  1^-in.  maple, 
Paper, 

Erect  hardware  on, 

Window  weights, 
Window  cords, 
Spikes,  bolts,  etc,. 
Anchors,  etc., 
Hauling, 
Hoisting, 


285,000ft.  B.  M.  at  $35. 00 

57,000  sq.  ft.  gross  .  05 

85,100  sq.  ft.  gross  .08 

75,000  .071 

59,400  sq.  ft.  gross  .005 

{460  yandows  1 
23  doors         / 

15  tons  30.00 

9,200  lin.  ft.  .04 

200  kegs  S.fcO 

5,000  lb.,  .04 

1,400  tons  .75 

685,000  .50 


9,975 
2,850 
6,808 
4,600 
300 

240 

450 
368 
600 
200 
1,050 
342 

26,733 


LIST  OF  SUB-BIDS 


Iron  and  Steel: 


Bid  A. $45,725 

Bid  B ' 40,620 

BidC.. 38,550 

Bid  D  (stairs,  guards,  ladder  only) 6,085 

Iron  Doors: 

Bid  A 9,589 

Bid  B 9,162 

Painting: 

Bid  A 3,856 

Bid  B 2,897 

BidC 2,400 

Roofing: 

Bid  A 1,613 

Bid  B 1,495 

BidC 1,400 

Plumbing: 

Bid  A 8,875 

Bid  B 8,160 

BidC 6,440 

Plastering: 

Bid  A 760 

BidB..  730 


ESTIMATING  345 

Mill  Work: 

Bid  A 5,500 

Bid  B 5,025 

Glazing: 

Bid  A 1,587 

Bid  B 1,352 

Terra  Cotta: 

Bid  A 1,370 

Bid  B 1,125 

Marble: 

Bid  A 372 

Sheet  Metal: 

Bid  A 4,280 

Bid  B 3,531 

Bid  C 2,888 

BidD 2,730 

Bid  E .' 2,188 

BidF 2,059 

Reinforced  Concrete  and  Cellar  Floor: 

Bid  A 8,755 

ESTIMATE  SUMMARY 

SUPERSTRUCTURE  ONLY 

Three  Factory  Buildings,  Chicago 

1  building,  125X175,  1  story  and  basement,  A. 
1  building,  16x133,  2  story  and  basement,  B. 
1  building  112X230,  2  story  and  basement,  C. 

Superintendent  (4  months) $      560 

Foreman 500 

Watchman ; 100 

Office  and  sheds 200 

Telephone 50 

Barricade,  650  ft.  (lineal) 100 

Accident  insurance 700 

Fire  insurance 100 

Remove  rubbish  and  haul  scaffolding 500 

Water  permit 50 

5  temporary  stairs 100 

Plant 500 

Brick,  common  (1077  M.  at  $20.00) 21,540 

Brick,  face  (136  M.  at  $45.00) 6,120 


346     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Brick,  fire  (13  M.  at  $40.00) 520 

Tile  coping  (965  1.  f.  at  .20) 193 

Partition  tile,  6  in.  (18,800  sq.  ft.  at  .15) 2,820 

Partition  tile,  8  in.  (960  sq.  ft.  at  .17) 163 

Stone,  3800  cu.  ft 6,000 

Concrete  cellar  floor  (7  1/4  in.  at  :18) 8,658 

Concrete,  reinforced . 4,155 

Carpentry '.....'.. ?. 27,000 

Mill  work  (Bid  B) .' 5,025 

Mill  work  setting,  30  per  cent 1,675 

Terra  cotta  (Bid  B) ^     1,125 

Terra  Cotta  setting,  20  per  cent .  . . ' .        220 

Plastering  (Bid  B.) ' 730 

Painting  (Bid  C) 2,400 

Glazing  (Bid  B) 1,352 

Marble  and  mosaic  (Bid  A) 372 

Sheet  metal  (Bid  D) 2,730 

Roofing  (Bid  C)' .  , .  1,400 

Structural  steel  and  iron  (Bid  C) 38,550 

Iron  doors  (Bid  B) 9,162 

Plumbing  (Bid  C) 6,440 

Incidentals . .                                                3,000 


$154,810 
Profit,  5  per  cent 7,740 


$162,550 

EXAMPLE  No.  II 

The  second  etimate,  given  here  is  for  an  automobile  factory, 
75  feet  wide,  865  feet  long,  and  four  stories  high ;  with  reinforced 
concrete  frame,  and  walls  with  brick  facing,  but  composed  chiefly 
of  glass.     Alternate  design  also,  on  steel  framing. 
Excavation: 

General,  100X78X8J  ft.          =66,300  cu.  ft.  =2,455  cu.  yd. 
Trench,  1900  ft.  at  1£X4|  ft.  =  12,825  cu.  ft. 
Piers,  88  at  7^X7JX4J  ft.       =22,176  cu.  ft. 
88  at  6|  X6i  X4|  ft.       =  16,720  cu.  ft. 
7at2$X2fX4f  ft.       =      196  cu.  ft.  =  1,930  cu.  yd. 

Reinforced  Concrete: 
4  in.  floor  slabs. 

3  floors,  74X860  ft.  \  _ 
Iroof,     74X860  ft.  f        M'56 
6  in  floor  slabs,  60X74  ft.    =     4,440  sq.  ft. 
178  beams,  12X18  in.X   70  ft.  =    12,460  lin.  ft. 
44  beams,    6X12  in.X 780  ft.  =   34,320  lin.  ft. 


ESTIMATING 


347 


Wall  Beams: 

780  ft.  beams  =  18X30  in. 
1,560  ft.  beams  =  16X24  in. 

780  ft.  beams  =  16X48  in. 
2,920  ft.  beams  =  8X24  in. 


6,040 
Columns: 

88  inside  columns,     16  X 16  in.  X  52  ft.  =4,576  lin.  ft. 
104  outside  columns,  16X24  in.X52  ft.  =  5,408  lin.  ft. 

Column  Piers: 

88  piers,  7X7  ft.XlS  in.  \ 

88  piers,  6X6ft.Xl8  in./  " 
860  ft.  parapet,  2|  ft.XS  in.  =  1,290  cu.  ft. 
and  2,700  sq.  ft.  =    700  cu.  ft. 


1,990  cu.  ft. 


Reinforced  Concrete  Summary. 

4  in.  slab,                        254,560  sq.  ft. 

84,853  cu.  ft. 

6  in.  slab,                            4,440  sq.  ft. 

2,220  cu.  ft. 

12  X  18  in.  beam,             12,460  lin.  ft 

18,690  cu.  ft. 

6  X  12  in.  beam,             34,320  lin.  ft 

17,160  cu.  ft. 

18  X  30  in.  beam,                  780  lin.  ft 

2,925  cu.  ft. 

16  X24  in.  beam,               1,560  lin.  ft 

4,160  cu.  ft. 

16X48  in.  beam,                  780  lin.  ft 

4,160  cu.  ft. 

8X24  in.  beam,               2,920  lin.  ft 

3,890  cu.  ft. 

Cols.  16  X  16  in.,                4,576  lin.  ft 

9,152  cu.  ft. 

Cols.  16X24  in.,                5,408  lin.  ft 

13,500  cu.  ft. 

Cols,  bases, 

11,220  cu.  ft. 

171,930  cu.  ft. 

Forms  for  slabs, 

260,000  sq.  ft. 

Forms  for  beams, 

52,820  lin.  ft. 

Forms  for  cols., 

9,980  lin.  ft. 

Cost. 

Concrete,                 172,000  cu.  ft.    at 

$.23   =  $  39,560 

Steel,                              576  tons       at 

50.00   =       28,800 

Steel  hauling,                576  tons       at 

.50   =            288 

Steel  erecting,               576  tons       at 

4.00   =         2,300 

Forms,  slabs,          260,000  sq.  ft.    at 

.06   =       15,600 

Forms,  beams,         52,800  lin.  ft.    at 

.30   =       15,840 

Forms,  cols.,             10,000  lin.  ft.   at 

.40   =         4,000 

Damp  proof,               3,200  sq.  ft.    at 

.05   =             160 

1  in.  surfacing,       260,000  sq.  ft.    at 

.05   =         7,800 

16  stairs,  4  ft.  wide, 

2,400 

$116,748 


348     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Brick. 


Foundation 


Tunnel  8-in.  wall,  18  ft.  X78  ft. 

210  ft.  8-in.  wall,  8  ft. 

260  ft.  17-in.  wall,  10  ft. 
20  ft.  17-in.  wall,  10  ft. 

370ft.     8-in.  wall,    7ft. 

870  ft.  12-in.  wall,  7  ft. 
1,470  ft.  8-in.  wall,  7  ft. 


Area  of  wall  in  square  feet. 
8-in.        12-in.        17-in. 
wall         wall          wall 
1,404 
1,680 

2,600 
200 


2,590 
10,290 


6,090 


15,964        6,090        2,800 


First  Story. 

44  pilasters,  5  ft.  X  8  in.  thick  X 11  ft.  high  = 

360-ft.  wall,  8  in.  thick  X 14  ft.  high  = 

50-ft.  wall,  17  in.  thick  X 14  ft.  high  = 

210-ft.  wall,  8  in.  thick  X 14  ft.  high  = 

80-ft.  wall,  17  in.  thick  X 14  ft.  high  = 


8-in.  wall 


17-in.  wall 


2,420 

5,040 

700 

2,940 

1,120 

10,400 

1,820 

Second  Story. 


210-ft.  wall, 

8  in.  X  12  ft.        = 

2,520 

360-ft.  wall, 

8  in.  X  12  ft.        = 

4,320 

80-ft.  wall, 

17  in.  X  12  ft. 

960 

80-ft.  wall, 

17  in.  X  12  ft.        = 

960 

6,840 


1,920 


Third  story,  same  as  second. 
Fourth  story,  same  as  second. 
Pent  house.      Solid  brick  walls. 


4  pt.  ho.  30  X  4  ft.  X  8  in.  =    480 
6pt.  ho.  60  X 15  ft.  X  8  in.  =5,400 


Brick  Summary. 


Solid  wall  in  foundation. 
15,964  sq.  ft.  wall,       8  in. 

6,090  sq.  ft.  wall,     12  in. 

2,800  sq.  ft.  wall,    28  in. 


at  14  bricks 
at  21  bricks 
at  28  bricks 


224,000  bricks 

128,100  bricks 

78,400  bricks 


430,500  bricks 


ESTIMATING 


349 


Hollow  and  face  brick. 

First  story, 
Second  story, 
Third  story, 
Fourth  story, 
Pent  house, 


8-in.  wall  17- in.  wall 

10,400  sq.  ft.  1,820  sq.  ft. 

6,840  sq.  ft.  1,920  sq.  ft. 

6,840  sq.  ft.  1,920  sq.  ft. 

6,840  sq.  ft.  1,920  sq.  ft. 
5,880  sq.  ft. 

36,800  sq.  ft.  7,580  sq.  ft. 


36,800  sq.  ft.    8-in.  wall  at  14  bricks    515,200  bricks 
7,580  sq.  ft.  17-in.  wall  at  28  bricks    212,240  bricks 


727,440  bricks 


Face  brick  =  40, 100, 

Hollow  brick  =  727,440-40,100  =  687,340  bricks. 

Reinforced  concrete:   design  with  steel  framing. 


Floors  and  roof,  4  74X860  ft. 

4-in.  floor  slabs, 
6-in.  floor  slabs, 
12Xl8-in.  beam, 
6Xl2-in.  beam, 
Column  bases, 


254,600  sq.  ft. 

4,440  sq.  ft. 

12,460  lin.  ft. 

24,960  lin.  ft. 

416  cu.  yd. 


84,853  cu.  ft. 
2,220 
18,690 
12,480 
11,220 


129,463 


Forms  for  slabs 
Forms  for  beams 

Cost. 


=  260,000  sq.ft. 
=  37,420  lin.  ft. 


Concrete,  130,000  cu.  ft. 
Steel,  400  tons 
Steel,  400  tons,  hauling 
Steel,  400  tons,  setting 
Forms,  slabs,  260,000  sq.  ft. 
Forms,  beams,  38,000  lin.  ft.  at 
1-in.  surfacing,  260,000  sq.  ft.  at 


16  stairs,  4  ft.  wide 


at 


at     $.30   = 

$39,000 

at  50.00   = 

20,000 

at       .50   = 

250 

at     4.00   = 

1,600 

at       .06   = 

15,600 

at       .30   = 

11,400 

at       .03   = 

7,800 

150.00   = 

2,400 

$98,050 


Brick:   design  with  steel  framing. 


16-in.  wall  beams, 
16-in.  wall  cols., 


6,200  lin.  ft.    15,135  cu.  ft. 
5,408  lin.  ft.    13,500  cu.  ft. 


28,600  at  21  =600,600  bricks 


350     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Above  divided  as  follows: 
Face  brick,  100,000  at 

Common  bricks,  500,000  at 

230  stone  sills,  17  ft.  long  ==3910  ft.     at 
88  Col.  casings,  4  ft.  around  X  50  ft. 
=  352  M.  at 


$45. 
18. 
.50 


$4,500 
9,000 
1,955 


$18.      =       6,336 


21,791 


LIST  OF  SUB-BIDS 
Round  high-carbon  steel  bars 


3/  4to  1/4  in.,  $1.52  1/2 

5/8  in.,  1.571/2 

1/2  in.,  1 .62  1/2     F.O.B.  in  car-load  lots 

3/8  in.,  1.771/2 

List  of  Sub-bids,  continued. 
Sheet  Metal  and  Roofing: 

Covering  Total 

Metal        Doors         For  For 

only          only         cone.        steel 
design      design 

Bid  A.     Gutters,  cornice,  flash- 
ing, conductor  heads $1,000     

Bid  B: 

For  concrete 1,483         $931      

For  steel  frame 1,834 

Bid  C 995        1,025     

Bid  D 1,161      

Bid  E $2,246      $2,884 

Bid  F 3,454        4,172 

Bid  G 3,000        3,408 

Bid  H 2,900        3,800 

Bid  1 3,063        3,609 

Bid  J 3,448        3,905 

Glazing: 

Bid  A $3,725 

Painting: 

Painting  and  Painting 

glazing  only 

Bid  A $7,480  

Bid  B $4,300 

BidC 4,500 

'    BidD 4,656 

Bid  E 8,300  

BidF 9,150  

Bid  G 8,426  

BidH 9,925  


ESTIMATING 


351 


Carpentry: 


Bid  A 

Mill          If  win< 
work            are 
only              duci 

$4  ( 

iows 
de-              Total 

bed 

)00            $19,959 
L33              17,482 

16,431 
15,134 

Magnesia      Air  cell 
covering      covering 

$22,208      
15,000        $14,300 

Bid  B  
Bid  C 

4,: 

$10  485 

Bid  D  
Bid  E                       .... 

Heating: 
Bid  A 

As  per          With 
plan         asbestos 
covering 
$19  308       $18  108 

Bid  B  
Bid  C 

.  .  .      14,684          13,907 
16  300          16  500 

Bid  D  
Bid  E1  
Bid  F  

.  .  .       15,664          15,044 
.  .  .       15,700     

14,939          14,611 

Plumbing: 

Bid  A  
Bid  B 

Per  plan 

$10,287 
8  974 

Special 
.$  8,987 

BidC  
Bid  D 

12  535 

11,482 

Miscellaneous  Iron: 
Bid  A  

F.  O.  B. 

$5  982 

Erected 

$8,279 

Bid  B 

Bid  C  

3,324 
6.859 

Bid  D.. 

Structural  Steel  (for  steel  frame      F.  O.  B.  Erected 

design) 

Bid  A $86,159 

Bid  B 82,370 

Bid  C $72,950  86,600 

Bid  D 75,000  

Excavating: 
Bid  A: 

Grading $2,420 

Crock  sewer  for  drainage 2,230 

12-in.  crock  ducts  for  heating 735 

1  Vacuum  system,  $17,402,  deduct  $270  if  air  cell  is  used  in  place  of 
magnesia  pipe  cover. 


352     ENGINEERING  OF  SHOPS  AND  FACTORIES 


ESTIMATE  SUMMARY 
For  Automobile  Factory  with  Concrete  Framing 


Excavation,  general, 
Excavation,  trench, 
Reinforced  concrete, 
Steel  F.  O.  B 
Steel  hauling, 
Steel  setting, 
Forms,  slabs, 
Forms,  beams, 
Forms,  columns, 
1-in.  surfacing, 


Brick,  common, 
Brick,  hollow, 
Brick,  face, 
Brick,  fancy  face, 
Tile  coping, 
Hydrolithic  coating, 


2,455yds.  $      .50 

1,930  .50 

172,000  cu.  ft.  .23 

576  tons  50 . 00 

576  tofli  .  50 

576  tons  4.00 

260,000  sq.  ft.  .06 

52,800  lin.  ft.  .30 

10,000  lin.  ft.  .40 

260,000  sq.  ft.  .03 

16  concrete  stairs,  4  ft.  wide  150.00 

Basement  floor,                  56,000  sq.  ft.  .14 

432,000  18.00 

687,300  16.00 

40,000  45.00 

3,100  80.00 

2101m.  ft.  .25 

7,000  sq.  ft.  .04 
.50 
.005 


43 

300,000  sq.  ft.  at 


Stone  sills,  17  ft.  long 

Cement  ceiling  wash, 

Iron  work,  F.  O.  B., 

Iron  work,  erection,  20  per  cent., 

Kinnear  doors, 

Mill  work,  erected, 

Tin  doors  and  covering 

Hardware,  pivots  and  screws, 

Hardware,  fire  door  fittings, 

Painting, 

Glazing, 

Sheet  metal  and  roofing  (sub-bid  E), 

Plumbing, 

Heating, 

Superintendent  for  15  months  at  $200, 

Foreman  for  15  months  at  $150, 

Watchman, 

Telephone, 

Water, 

Rubbish  clearing, 

Water  closet, 

Storage  sheds, 

Insurance, 

Liability, 

Bond,  1  per  cent,  on  1/4  of  contract, 

Temporary  stairs,  10  sets  at  $50 

Tools  and  plant, 

Traveling  expense, 


1,227 

965 

39,560 

28,800 

288 

2,300 

15,600 

15,840 

4,000 

7,800 

2,400 

7,840 

7,776 

11,000 

1,800 

240 

50 

280 

360 

1,500 

4,000 

800 

775 

10,300 

2,250 

1,200 

300 

3,400 

3,500 

2,250 

8,200 

14,000 

3,000 

2,500 

1,000 

100 

500 

1,000 

50 

500 

400 

2,500 

750 

500 

5,000 

200 


ESTIMATING  353 

Building  permit,  300 

Incidentals,  1  per  cent.,  2,500 

176  borings,  500 


23 


$221,843 
Profit,  5  per  cent.,  11,100 


$232,943 


CHAPTER  XXX 
CONSTRUCTION 

Having  completed  all  the  designs  and  specifications  for  a  plant, 
it  is  then  the  duty  of  the  engineer  to  secure  estimates  and  tenders, 
to  place  or  assist  in  placing  the  contract  for  construction  and  to 
superintend  the  work. 

Construction  work  may  be  carried  on  either  under  salaried 
superintendents  employed  by  the  owner,  or  the  work  may  be 
given  out  in  contracts.  In  the  first  method,  the  superintendent 
must  employ  men  in  the  various  trades,  buying  only  such  goods 
as  he  is  unable  to  produce.  When  construction  work  is  done  by  a 
contractor,  he  may  be  paid  in  any  one  of  the  following  ways: 

1.  A  lump  sum  for  the  whole  work. 

2.  Cost  price  plus  a  percentage. 

3.  Cost  price  plus  a  fixed  sum. 

4.  Cost  price  plus  a  percentage  in  inverse  proportion  to  the 
cost. 

Each  of  these  methods  has  some  advantages,  No.  1  being  the 
simplest  to  keep  track  of,  and  on  which  to  make  final  settlement. 
With  No.  2  there  is  always  the  incentive  for  the  contractor  to 
swell  the  cost  as  his  own  profits  increase  in  proportion,  but  in 
No.  3  this  incentive  disappears,  for  the  contractor's  profit  is 
fixed  and  independent  of  the  cost  of  the  building  to  the  owner.  In 
No.  4  it  is  plainly  to  the  contractor's  interest  to  keep  the  cost 
down  to  a  minimum,  for  the  less  the  owner  has  to  pay,  the  more 
the  contractor  receives. 

Estimates  and  Tenders. — A  careful  selection  should  be  made 
when  sending  out  invitations  for  tenders,  that  bids  may  be 
received  from  people  in  good  standing,  who  will  do  good  work  in 
an  honest  way.  In  order  to  avoid  local  combinations,  or  the 
collusion  of  bidders,  invitations  should  be  sent  to  concerns  widely 
separated  from  each  other.  The  engineer  is  generally  better  able 
than  the  owner  to  select  the  bidders,  for  an  acquaintance  with  the 
builders  is  part  of  his  business,  but  the  owner  will  probably  want 
prices  from  people  that  he  knows.  If  bids  are  received  from  a 

354 


CONSTRUCTION  355 

few  general  contractors  on  the  work  as  a  whole  and  on  the 
different  branches  of  work  from  sub-contractors,  the  engineer 
will  then  know  the  cost  in  detail,  and  he  can  award  the  work  to  a 
general  contractor  in  one  part,  or  separately  to  sub-contractors, 
as  economy  and  expediency  may  direct.  He  should  receive 
unit  prices  for  any  kind  of  work,  such  as  foundations,  which  may 
ultimately  be  more  or  less  than  shown  on  the  drawings.  If 
given  out  in  many  parts,  some  one  of  the  sub-contractors  must 
be  placed  in  charge,  and  his  contract  must  be  so  worded,  with 
extra  compensation  for  such  service. 

If  inquiries  are  made  by  contractors  respecting  any  uncer- 
tainties in  the  plans  or  specifications,  they  should  be  answered  by 
duplicate  letters,  sending  a  copy  to  each  bidder,  that  all  may 
have  exactly  the  same  data  and  information.  Sufficient  time 
should  be  given  for  making  careful  estimates,  for  if  hurried  too 
much,  contractors  will  add  a  percentage  for  uncertainties,  and 
bids  will  be  unreasonably  high.  Bids  should  be  submitted  in 
sealed  envelopes  plainly  marked  on  the  outside  with  the  word 
"Tender",  so  they  will  not  be  opened  until  the  proper  time,  a 
definte  date  having  been  previously  set  by  the  engineer,  after 
which  no  further  bids  would  be  received.  A  blank  form  of  con- 
tract should  be  enclosed  with  the  invitations  for  tenders,  so  the 
contractor  may  see  just  what  he  is  expected  to  sign.  This  con- 
tract should  be  drawn  up  by  an  attorney,  from  data  and  require- 
ments supplied  to  him  by  the  engineer  and  owner. 

When  time  for  receiving  bids  has  expired,  and  they  are  all 
in  possession  of  the  engineer,  they  should  then  be  opened  by  the 
engineer  and  owner  together,  and  the  various  items  tabulated 
for  easy  comparison,  and  in  making  such  comparison  it  must  be 
carefully  noted  just  what  is  included  in  the  price.  The  lowest 
bids  by  containing  something  that  is  not  required  sometimes  ap- 
pear to  be  high,  and  their  relative  values,  are  not  appreciated 
until  they  are  all  thoroughly  examined  as  to  the  work  included. 

Contracts. — The  engineer  should  remember  that  up  to  this 
time,  contractors  expecting  or  hoping  to  secure  profitable  work, 
have  been  free  with  offers  and  promises  and  have  probably  shown 
nothing  but  good  will.  But  with  the  signing  of  a  contract, 
new  conditions  begin,  for  motives  are  now  different,  the  contrac- 
tor desiring  to  make  the  largest  possible  profit  for  himself,  and  the 
owner  to  get  the  best  building  he  can  for  the  least  money  and  to 
get  it  at  the  time  agreed  upon.  As  the  mechanical  equipment  is 


356     ENGINEERING  OF  SHOPS  AND  FACTORIES 

so  different  to  the  building  construction,  the  installation  of  this 
is  usually  let  in  a  separate  contract.  This  will  include  the 
heating,  lighting,  plumbing,  power  and  water  supply,  fire  pro- 
tection, and  elevators.  These  are  wholly  the  designs  of  me- 
chanical engineers. 

Superintendence. — This  work  may  be  done  either  by  the  owner 
with  the  assistance  of  a  salaried  superintendent,  or  under  the 
direction  of  the  engineer.  The  latter  method  is  without  question 
the  best,  for  the  man  who  produces  a  design  certainly  knows 
better  than  any  one  else,  how  he  wants  it  carried  out. 

Engineers  and  architects  who  give  their  best  thought  to 
questions  of  design  usually  have  associated  with  them  men  who 
are  efficient  in  superintendence,  and  many  of  the  larger  offices 
have  regularly  organized  departments  for  construction  and 
superintendence.  Yards  and  grounds  must  be  laid  out  with 
their  tracks  and  sidings,  buildings  erected  and  equipment  in- 
stalled, including  cranes,  special  machinery  and  mechanical 
installation.  As  the  work  progresses  monthly  estimates  and 
reports  of  the  amount  of  work  done  must  be  made  by  the  engineer 
and  submitted  to  the  owner,  for  on  these  the  contractor  receives 
his  progress  payments.  Photographs  should  be  freely  made,  as 
they  are  a  sure  record  of  conditions,  and  often  avoid  or  settle 
future  disputes.  Harmony  in  dealings  is  always  desirable,  and  yet 
the  engineer  must  not  always  conciliate  merely  to  preserve  peace. 

When  construction  is  completed  and  the  plant  finished  in  all 
its  parts,  the  site  should  be  put  in  a  clean  and  neat  condition 
ready  for  acceptance  by  the  owner.  Final  estimates  must  then 
be  made  by  the  engineer,  and  when  the  work  has  been  accepted 
and  paid  for,  the  engineer's  duties  terminate. 


CHAPTER  XXXI 
WELFARE  FEATURES 

A  book  on  modern  factories  would  not  be  complete  without 
reference  to  the  provisions  which  are  now  so  generally  made  for 
the  comfort  and  welfare  of  employees.  Such  measures  are  intro- 
duced not  for  philanthropic  but  for  purely  commercial  reasons, 
because  "  it  pays."  Under  agreeable  conditions,  men  and  women 
will  do  more  and  better  work  than  they  would  if  uncomfortable 
or  dissatisfied.  Establishments  have  found  that  in  order  to 
produce  economically,  they  must  permanently  retain  a  large 
proportion  of  their  operatives  because  the  constant  training  of 
new  ones  is  too  expensive.  Attractive  conditions  are  therefore 
created  to  draw  and  hold  employees  and  keep  them  contented, 
in  order  to  increase  their  productiveness  and  efficiency.  It  is 
difficult  to  compute  the  money  value  of  this  increase,  but  there 
is  no  doubt  that  willing  and  cheerful  workers  can  do  more  than 
those  who  labor  under  compulsion. 

The  subject  will  be  discussed  under  the  following  headings: 

1.  Social  relations. 

2.  Health  conditions. 

3.  Pleasant  surroundings. 

4.  Material  benefits. 

5.  Educational  advantages. 

6.  Opportunity  for  recreation. 

Social  Relations.— The  beginning  of  a  new  era  in  factory 
construction  was  the  outgrowth  of  necessity.  That  old  time 
friendship  and  acquaintance  which  once  existed  between  owner 
and  employee,  had  long  since  ceased;  and  in  many  cases,  in 
order  to  earn  their  daily  bread,  men  were  driven  by  necessity  to 
work  in  dirty  and  grimy  shops,  going  daily  to  their  work  with 
no  more  willingness  than  would  be  aroused  in  going  to  a  prison. 
Under  such  conditions  they  gave  only  enough  service  to  hold 
their  place,  and  changed  often  from  one  factory  to  another,  to 
relieve  the  drudgery  and  monotony  of  life.  Little  or  no  interest 
was  shown  in  them,  and  constant  friction  existed  between  the 

357 


358     ENGINEERING  OF  SHOPS  AND  FACTORIES 

workmen  and  their  foremen  who  were  intolerant  and  domineering, 
much  like  slave  drivers.  Under  the  lash  of  necessity,  the  sullen 
worker  produced  only  when  watched  and  driven,  and  balked  at 
every  opportunity.  When  conditions  finally  became  intolerable 
for  the  worker,  and  without  profit  to  the  owner,  a  change  was 
inevitable.  ^ 

Conditions  in  some  places  have  now  swung  almost  to  the  other 
extreme,  and  welfare  features  are  introduced  to  such  an  extent 
as  to  detract  attention  from  the  company's  business.  Large 
industries  now  make  the  interest  of  their  workers  a  definite 
part  of  their  business,  and  for  this  purpose  a  welfare  manager 
and  social  secretary  are  appointed,  one  each  for  the  men's  and 
women's  departments  respectively.  The  duty  of  these  persons 
is  to  study  and  care  for  the  workers  needs,  and  to  act  as  inter- 
mediary between  them  and  the  owners.  Diplomatic  persons  in 
these  positions  soon  gain  general  confidence,  and  men  and  women 
will  freely  tell  their  wants  to  them,  with  prospect  of  relief. 
Under  the  new  and  better  regime,  men  and  women  treated  as 
human  beings  have  regained  self  respect.  Women  workers, 
who  were  formerly  all  "girls,"  "hands,"  or  "help,"  now  receive 
the  more  respectful  "Miss,"  and  men,  when  passing  through 
the  women's  workrooms,  remove  their  hats  as  they  would  at 
home.  Under  these  conditions  employers  rightfully  expect  a 
better  education  in  those  that  they  employ,  and  in  many  factories 
graduation  from  a  high  school  is  now  one  of  the  necessary 
qualifications. 

The  attitude  of  the  factory  to  the  public  is  also  changed,  for 
a  welcome  to  visitors  is  now  a  common  and  definite  policy. 
Reception  rooms  are  provided  and  furnished,  and  guides  are 
delegated  to  conduct  persons  about,  often  meeting  visitors  with 
a  conveyance  at  the  nearest  depot,  and  escorting  them  to  the 
works.  Balconies  or  galleries  afford  a  panorama  of  the  work 
in  operation,  and  elevators  lead  to  an  observation  tower  where 
a  view  is  obtained  of  the  plant  and  its  surroundings.  New 
factory  conditions  are  so  greatly  appreciated  by  the  public  that 
their  owners  or  managers  are  usually  entitled  to  respect  and 
confidence.  One  modern  and  almost  ideal  plant  for  which  the 
writer  made  elaborate  plans  was  so  highly  esteemed  by  the 
citizens  that  the  return  of  its  president  from  a  world  tour  was 
accompanied  by  a  great  demonstration.  A  special  train  with 
a  hundred  representative  men  went  out  to  meet  him  and  escort 


WELFARE  FEATURES  359 

him  home  and  40,000  people  paraded  the  streets  in  his  honor 
and  presented  him  with  a  loving  cup. 

Health  Conditions. — No  argument  is  needed  to  show  that 
healthy  bodies  are  essential  to  efficient  work.  The  following 
health  requirements  should  therefore  be  maintained: 

1.  General  cleanliness  of  buildings  and  occupants. 

2.  Abundance  of  washing  and  bathing  facilities. 

3.  Good  light,  and   pure  air  of  the  right  temperature  and 
humidity. 

4.  Regular  working  hours,  with  sufficient  time  for  rest  and 
recreation. 

With  these  requirements  fulfilled,  there  should  be  enthusiasm 
during  working  hours. 

In  order  to  start  right,  applicants  should  pass  a  health  exam- 
ination before  being  given  employment. 

The  building  should  be  swept  daily,  and  washed  out  once  a 
week,  and  this  work  will  require  the  service  of  one  janitor  for 
about  fifty  employees,  or  four  for  every  acre  of  floor  space. 
Spitting  should  be  prohibited.  In  some  plants  where  a  large 
number  of  women  are  employed,  they  may  be  supplied  with 
clean  aprons  and  half  sleeves  twice  per  week.  This  will  average 
about  ten  articles  per  week  for  the  laundry  for  each  person.  In 
large  establishments  a  steam  laundry  may  be  maintained,  and 
to  avoid  disagreeable  odors  it  should  be  on  an  upper  floor. 
Windows  should  be  regularly  cleaned  and  curtains  renewed 
when  they  are  soiled.  In  shops  as  elsewhere,  order  and  cleanli- 
ness promote  self  respect,  but  interest,  inspiration  and  energy 
are  lost  when  working  amid  dirty  surroundings. 

Lavatories  and  shower  baths  are  now  prescribed  by  law  in 
many  states,  and  some  shops  permit  employees  to  take  two  baths 
per  week  in  summer  and  one  in  winter  during  working  hours. 
Occupants  in  some  departments  of  paint  works  are  required  to 
bathe  daily  to  prevent  possibility  of  lead  poisoning.  Hot  and 
cold  water,  towels  and  soap  should  be  provided  free,  for  if  any 
charge  is  made,  their  generaluse  will  be  limited.  Plants  where 
light  machinery  is  made  should  have  one  shower  bath  for  every 
twenty  to  thirty  persons,  and  some  foundries  have  one  bath  and 
shower  for  every  man.  A  swimming  tank  in  the  basement  may 
be  supplied  for  those  who  like  to  use  it. 

Good  light  and  pure  air  are  essential  to  health.  A  vacuum 
system  should  be  used  in  polishing  rooms,  and  suction  hoods 


360     ENGINEERING  OF  SHOPS  AND  FACTORIES 

hung  over  tables  where  dust  or  odors  are  evolved.  This  is 
especially  important  in  shops  making  cloth  or  cotton  goods, 
where  the  dust  often  produces  throat  and  lung  disease.  In  one 
cotton  mill  in  England,  no  less  than  74  per  cent,  of  all  the  workers 
were  thus  affected.  Air  can  be  cooled  in  summer  by  passing  it 
through  a  spray  chamber  before  forcing  it  up  through  the  build- 
ing, and  at  forges  and  rolling  mills  this  may  be  actual  economy, 
as  it  permits  continuous  instead  of  spasmodic  work  before  the  hot 
and  open  fires. 

Energy  should  be  conserved  for  useful  purposes,  and  operatives 
and  especially  women,  should,  in  multi-story  buildings  have  free 
use  of  elevators.  Women  should  also  have  high-backed  chairs 
and  footstools  for  occasional  or  continuous  use,  and  they  should 
be  dismissed  ten  to  fifteen  minutes  earlier  than  men  at  night  and 
come  later  in  the  morning,  so  they  may  find  seats  in  the  street 
cars.  Some  shops  also  give  morning  and  afternoon  recess  of 
ten  minutes  for  relaxation.  Shops  employing  women  should 
have  a  rest  room  with  comfortable  chairs  and  lounges,  and  large 
works  often  have  .a  regular  nurse  in  attendance.  This  room 
should  contain  a  case  of  medicines,  plasters,  bandages  and  other 
things  needful  in  emergencies,  and  arrangements  should  be  made 
with  physicians  that  one  will  always  be  within  immediate  reach. 
Foremen  should  be  instructed  in  methods  of  rendering  aid  in 
case  of  accident.  The  shop  should  occasionally  be  visited  by 
the  company's  oculist,  to  serve  any  who  may  need  attention. 

Pleasant  Surroundings. — Next  to  healthful  conditions,  pleasant 
surroundings  are  perhaps  the  most  attractive.  The  largest 
facilities  in  this  direction  are  offered  in  suburban  districts,  where 
enough  land  is  obtainable  for  a  lawn  or  park.  In  landscape 
gardening,  large  grass  areas  should  remain  unbroken,  and 
shrubbery  and  flowers  concentrated  in  masses.  A  pond  or 
lagoon  adds  beauty  by  its  contrast.  The  roofs  of  multi-story 
shops,  which  are  usually  neglected,  may  be  turned  into  a  roof 
garden  or  promenade,  and  partly  covered  with  canvas  awnings. 

The  building  interior  may  be  painted  in  pleasing  colors,  light 
green  or  brown  being  suitable  for  the  walls,  with  a  dado  of  darker 
shade,  and  cream  or  some  warmer  tint  for  the  ceiling.  White 
wash  for  this  purpose  is  no  longer  favored.  A  limited  number  of 
mottoes  or  pictures  on  the  walls  are  appropriate  to  relieve  their 
monotony,  and  these  may  occasionally  be  changed  or  rearranged. 
Machinery  which  is  enameled,  or  painted  a  nickel  color,  adds 


WELFARE  FEATURES  361 

greatly  to  the  appearance  and  cleanliness  of  the  shop,  for  when 
it  is  soiled  it  can  easily  be  washed  off  again.  In  some  larger 
printing  establishments,  as  that  of  the  McGraw-Hill  Publishing 
Company,  the  machinery  is  enameled  white,  thus  assuring 
cleanliness,  attractiveness,  and  better  light. 

Material  Benefits. — Features  which  result  in  material  benefit 
to  the  workers  are  often  most  appreciated  and  these  include 
co-operative  or  profit  sharing  systems,  membership  in  insurance 
or  mutual  aid  associations,  and  the  provision  of  meals  at  cost 
price.  Profit  sharing,  used  by  such  concerns  as  Proctor  and 
Gamble  of  Cincinnati,  offer  an  incentive  to  effort,  and  the  sug- 
gestion system  used  by  the  National  Cash  Register  Company, 
and  previously  described,  offers  prizes  to  those  who  supply 
valuable  ideas  or  suggestions  which  can  be  utilized.  The  value 
of  this  system  is  evident  when  it  is  considered  that  each  trained 
worker  is  a  specialist  in  his  own  line,  and  should  know  more 
about  its  details  than  anyone  else.  He  should  therefore  be  able 
to  suggest  improvements  that  may  not  have  occurred  to  others. 
The  system  is  valuable  also  in  the  sales  department.  Workers 
all  become  partners  in  the  business,  and  instead  of  being  a  one- 
or  two-man  industry,  the  business  may  be  increased  to  a  thou- 
sand-brain-power or  more,  depending  upon  the  number  that  are 
employed. 

Mutual  aid  or  fraternal  associations  may  be  organized  for  the 
benefit  of  a  single  industry,  the  object  being  to  supply  at  least 
a  half  income  for  workers  that  are  sick.  Dues  can  be  propor- 
tioned to  the  needs,  though  one-half  of  1  per  cent,  of  the  regular 
wages  is  usually  enough.  A  shop  with  one  thousand  employees 
would  at  this  rate  contribute  $50  to  $75  per  week,  but  if  more 
money  is  needed  the  dues  can  be  increased,  and  if  all  is  not 
required,  collections  can  be  temporarily  suspended.  Experience 
shows  that  medical  service  for  such  an  association  would  cost 
about  $500  per  year,  for  there  would  seldom  be  more  than  three 
or  four  sick  at  one  time. 

Perhaps  the  greatest  practical  benefit  that  can  be  offered  to 
workers  is  the  supply  of  substantial  hot  dinners  at  cost  price. 
Men  bringing  cold  and  often  poorly  cooked  food  naturally 
fatigue  sooner  than  others  who  are  better  nourished.  One  large 
factory  employing  over  3000  persons  supplies  noon  lunches  to 
women  at  a  charge  of  only  25  cents  per  week,  and  to  men  for 
about  $1  per  week,  and  those  who  must  work  overtime  are 


362     ENGINEERING  OF  SHOPS  AND  FACTORIES 

given  evening  dinner  at  the  factory.  At  the  Krupp  works  in 
Germany  the  families  of  the  workers  are  allowed  to  unite  in  the 
company  dining  hall,  and  in  some  plants  the  dining  halls  over- 
looking a  lawn  or  park  are  provided  with  wide  verandas  or 
balconies  on  which  meals  are  served  in  summer.  Quick  lunch 
counters  may  also  be  maintained,  and  other  rooms  with  tables 
and  benches  only  for  those  who  prefer  to  bring  their  food. 
Under  good  management  the  preparation  of  meals  will  require 
one  cook  and  two  or  three  assistants  for  every  200  persons.  It 
would  seem  that  many  works,  especially  those  in  Europe,  are 
vying  with  each  other  in  the  abundance  of  their  altruistic 
measures. 

Educational  Measures. — Work  in  this  direction  is  educational, 
entertaining,  and  a  recreation.  A  library  of  books  and  all  the 
magazines  and  journals  relating  to  the  particular  business  should 
be  within  reach  of  all,  because  educated  minds  are  more  efficient 
than  others.  In  large  works  truck  loads  of  books  may  be 
circulated  through  the  shops  during  the  noon  hour,  though  it 
is  usually  best  for  everyone  to  have  a  walk  in  the  open  air  after 
lunch  and  before. returning  to  the  afternoon's  work.  Technical 
and  trade  papers  and  journals  are  a  great  benefit  to  the  workers 
and  consequently  to  the  factory  owners,  for  individuals  can 
seldom  afford  more  than  one  or  two  of  their  own.  They  should, 
therefore,  be  freely  supplied  as  an  important  part  of  the  shop 
equipment. 

Evening  classes  and  lecture  courses  are  another  means  of 
education  for  those  who,  from  lack  of  time  and  money  would 
otherwise  be  without  them.  Large  works  frequently  erect  a 
separate  building  as  a  center  of  social  and  educational  life  for 
their  employees,  and  this  building  may  have  a  properly  equipped 
auditorium  for  lectures  and  entertainments.  Instruction  classes 
may  be  established  to  any  extent  that  interest  and  attendance  will 
warrant,  all  such  work  being  under  the  direction  of  the  welfare 
manager  or  social  secretary,  though  the  details  of  management 
must  be  left  to  the  employees.  In  large  manufactories  classes 
for  men  may  be  maintained  in  drawing,  salesmanship,  languages, 
etc.,  and  for  women  in  cooking,  nursing,  stenography,  sewing, 
embroidery,  and  dancing.  Lectures  may  be  either  instructive  or 
entertaining,  or  both. 

Recreation. — A  club  for  recreation  and  entertainment  may  be 
organized,  but  it  should  be  free  from  the  works  management,  for 


WELFARE  FEATURES  363 

paternalism  in  industrial  works  is  usually  disastrous,  as  illus- 
trated by  the  town  of  Pullman.  Men  and  women  working  all  day 
under  the  direction  of  others  will  insist  on  freedom  of  action  after 
working  hours,  and  while  the  club  building  may  adjoin  the 
works  it  should  be  outside  of  the  company's  property.  The 
building  may  be  equipped  with  games,  pool  tables,  bowling  alley, 
piano,  and  gymnasium.  One  company  in  Brooklyn  owns  and 
operates  a  building  in  the  mountains  for  a  summer  camp,  and 
another  gives  a  ten  days'  summer  outing  in  tents  by  the  water  to 
one  thousand  employees  at  a  total  cost  of  less  than  $6  each. 
Vegetable  gardens  in  which  boys  and  men  can  work  and  grow 
products  for  their  own  use  have  proved  quite  popular  and  are 
not  only  a  source  of  profit  to  the  workers,  but  a  healthful  exercise 
and  recreation. 

The  suggestions  given  above  can  be  modified  or  extended  as 
desired,  to  suit  the  size  of  plant  and  the  wishes  of  its  occupants, 
and  though  only  a  few  of  these  suggestions  may  be  put  into  opera- 
tion at  any  particular  industry,  some  provision  for  the  benefit  and 
welfare  of  the  workers  should  be  part  of  all  such  organizations. 


CHAPTER  XXXII 
STANDARD   BUILDINGS 

The  following  tables  give  standard  sizes  with  estimated  weights 
for  typical  steel-framed  sheds  30  to  80  ft.  in  width,  with  clearance 
under  the  trusses  of  12  to  20  ft.  As  the  figures  given  are  on  sepa- 
rate units,  complete  estimates  can  readily  be  made  on  buildings 
of  any  length  (Fig.  175). 

The  buildings  are  proportioned  for  a  live  load  of  only  30  pounds 


FIG.  175. — Metal  covered  steel  framed  building. 

per  square  foot,  and  are  especially  designed  for  export  to  warm 
climates,  but  are  also  suitable  for  other  places  where  they  are  for 
shelter  and  enclosure  only,  and  not  for  supporting  cranes,  ma- 
chinery, or  heavy  loads.  Ventilators  may  be  included  or  omitted 
as  desired.  The  tables  refer  to  the  framing  only,  and  do  not  in- 
clude windows,  doors,  corrugated  iron,  louvers,  or  other  sheet 
metal,  nor  do  they  include  the  foundations.  Because  of  the  light 
loads  for  which  the  framing  is  proportioned,  they  are  suitable  only 
for  light  covering  such  as  corrugated  iron,  and  not  for  heavy  plank 
sheathing. 

As  ocean  freight  rates  depend  both  on  the  weight  and  space 
occupied  in  the  vessel,  space  is  left  in  the  tables  for  both  kinds  of 
data,  though  in  many  places  the  columns  are  left  blank,  to  be 
filled  out  by  the  user  to  suit  local  conditions  and  current  prices. 

365 


366     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE 
MATERIAL  FOR  BUILDING  30'0"  WIDE 


Heights 

Roof 

trusses 

Side 
columns 

End 

columns 

Knee 
braces 

Roof 
purlins 

Side 
purlins 

Purlin 
finish 
angles 

1 

12'0" 

See 
tables 

1  <2*X2Xft 
1-6"  ]-8  Ib. 

(each) 
l-5"I-9.75  Ib. 

2  <s 

2£X2Xft 

j-a 

<s 

3*X2*X1 

<8 

2iX2XiJ8 

< 

2iX2XA 

2 

14'0" 

•« 

1   <3X2Xi 
l-6"]-81b. 

1-6"I-121 

" 

:'«     • 

M 

3 

16'0" 

" 

4  <s 

2*X2X1 

•• 

2  <s 

2*X2Xi 

.... 

«~:: 

» 

4 

18'0" 

" 

" 

1-7"  1-15 

" 

" 

«« 

" 

5 

20'0" 

" 

" 

1-8"  1-18 

" 

" 

M 

" 

MATERIAL  FOR  BUILDING  35'  0"  WIDE 


6 

12'0" 

M 

1  <2iX2XA 
l-«"  ]-8  Ib. 

1-5"  I 

2  <s 

2iX2Xi3« 

<s 

3iX2iXl 

<s 

2iX2XA 

< 

2iX2Xi3H 

7 

14'0" 

" 

1  <  3X2X1 
1-6"  }-8  Ib. 

1-6"! 

- 

•• 

M 

8 

16'0" 

4  <s 

2iX2Xl 

" 

2  <s 

2iX2Xl 

2  <s 

2^X2X1 

« 

9 

18'0" 

•' 

4  <s 

3X2Xi 

1-7"  I 

««, 

" 

3 

10 

20'0" 

" 

" 

1-8"  I 

i< 

" 

"             |                     " 

MATERIAL  FOR  BUILDING  40'  0"  WIDE 


11 

12'0" 

M 

1   <  2}X2X& 

1-6"  ]-8 

1-5"  I 

2  <s 

2iX2Xi3e 

4"]-5.5 

< 
21X2X1 

< 

3X2X1 

12 

14'0" 

M 

1  <  3X2X1 
1-6"  ]-8  Ib. 

1-6"! 

•« 

«• 

" 

«• 

13 

16'0" 

" 

4  <s 

2JX2X1 

<• 

2  <s 

2JX2X1 

" 

" 

« 

14 

18'0" 

" 

4  <s: 

3X2X1 

1-7"  I 

•• 

•• 

«' 

15 

20'0" 

" 

M 

1-8"  I 

" 

" 

STANDARD  BUILDINGS 


367 


XXX 

X   30'0"  LONG,  10  FT.  PANELS 


Purlin 
ties 

Purlin 
clips 

Eave  strut 
at  ends 

Bracing 
between 
rafters 

Long'l 
bracing 

Long'l 

struts 

Bracing 
on  tie 
beams 

End 
purlins 

End 
rafters 

1  Line 

rods'  §  "  0 

< 
3X2Xi 

i"  0  rods 

|"  0  rods 

Pipe 
2£"  w.i. 

< 

3iX2iX  J 

l-Q"  ]_g  lb 

" 

" 

" 

** 

" 

" 

" 

«• 

" 

» 

" 

•• 

4i 

•• 

•• 

» 

" 

" 

•• 

" 

,, 

,i 

i, 

,, 

,, 

,, 

„ 

X40'  0"  LONG,  10  FT.  PANELS 

'• 

•• 

f'O  rods 

f'O  rods 

Pipe 
2,1"  w  i. 

2iX2X!38 

1-6"] 

- 

« 

» 

" 

« 

» 

•• 

•« 



•• 

M 

" 

•• 

M 

" 

•' 

M 

" 

" 

" 

» 

" 

" 

" 

" 

" 

" 

" 

X48'  0"  LONG,  12  FT.  PANELS 


'0  rods 


f  "0  rods 


Pipe 


368     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE 
MATERIAL  FOR  BUILDING  45'  0" 


Heights 

Roof 

trusses 

Side  columns 

End  columns 

Knee 
braces 

Roof  purlins 

Side  purlins 

Purlin 
finish 
angles 

See 

l<Sft*»Xft 

.(each) 

2< 

<s 

< 

16 

12'0" 

tables 

1-7"  1-9.75 

1-5"! 

Sffx2XT3s 

4"  1-5.5 

2^X2X1 

3X2X1 

<   3X2X1 

17 

14'0" 

** 

1-7"  }-9.75 

1-6"! 

" 

" 

" 

4  <s 

2  < 

18 

16'0" 

11 

3X2X1 

" 

2JX2X1 

" 

*  ' 

" 

19 

18'0" 

» 

" 

1-7"  I 

•• 

« 

.. 

•• 

20 

20'0" 

» 

" 

1-8"  I 

" 

" 

" 

" 

MATERIAL  FOR  BUILDING  50'  0" 


21 

12'0" 

•• 

1  <    3X?X1 
1-7"  ]-9.75 

1-5"  I 

2  <s 

2iX2Xa3e 

5"  ]-6.5 

<s 

3X2X1 

< 

3X2X1 

22 

14'0" 

»• 

1  <   3X2X1 
1-7"  ]-9.75 

1-6"! 

« 

" 

" 

23 

16'0" 

M 

4  < 

3X2X1 

» 

2  <s 

2iX2Xl 

„- 

.„ 

" 

24 

18'0" 

<« 

4  < 

3iX2iXl 

1-7"  I 

» 

" 

•• 

» 

25 

20'0" 

" 

" 

1-8"  I* 

" 

" 

" 

MATERIAL  FOR  BUILDING  55'  0" 


26 

12'0" 

" 

4  <s 

2X2X1 

1-5"  I 

2  <s 
2JX2X& 

5"]-6.5 

<s 

3X2X1 

<^- 

3X2X1 

27 

14'0" 

- 

4  <s 

2iX2Xi 

1-6"! 

•• 

" 

" 

28 

16'0" 

" 

4  <s 

3X2X1 

. 

2  <s 

2JX2X1 

" 

" 

29 

18'0" 

" 

4  <s 

3iX2iXi 

1-7"  I 

•• 

" 

" 

•• 

30 

20'0" 

11 

" 

18-"  I 

" 

" 

" 

" 

STANDARD  BUILDINGS 


369 


XXX. — Continued 
WIDE  X  48'  0"  LONG,  12  FT.  PANELS 


Purlin 
ties 

Purlin 
clips 

Eave  strut 
at  ends 

Bracing 
between 
rafters 

Long'l 
bracing 

Long'l 
struts 

Bracing 
on  tie 
beams 

End 
purlins 

End 

rafters 

i"0 

< 

3X2Xi 

f  "0  rods 

f  "0  rods 

Pipe 
3fc"  dia 

<s 

2iX2Xi3a 

<s 

3iX2£Xl 

1_6"  ]_g  ib 

» 

M 

" 

" 

" 

" 

- 

.'••«    ' 

•« 

• 

M 

•• 

" 

'.V                 " 

•• 

•• 

•• 

" 

". 

" 

•• 

.  ;:v  i 

" 

•• 

"  . 

" 

" 

'  " 

" 

" 

WIDE  X  56'  0"  LONG,  14  FT.  PANELS 


r-o 

3X2Xi 

2  <  laced 

|"0  rods 

f'O  rods 

Pipe 
4"  dia. 

<s 

<s 

/1-7" 
\  ]-9.75  Ib. 

" 

•• 

" 

•• 

- 

M 

« 

» 

" 

» 

» 

M 

•• 

•• 

" 

" 

.. 

- 

» 

„ 

•• 

•• 

- 

- 

11 

" 

" 

" 

" 

" 

" 

" 

" 

WIDE  X  56'  0"  LONG,  14  FT.  PANELS 

f'O 

3X2Xi 

2  < 

f'O  rods 

f'O  rods 

Pipe 

4"  dia. 

<s 

<s 

3X2Xi 

1-6"  ]-8  Ib. 

•• 

•• 

M 

•• 

- 

' 

" 

•• 

•• 

» 

«• 

» 

.. 

•• 

» 

M 

•• 

« 

•• 

•• 

<• 

" 

•• 

M 

- 

11 

" 

" 

" 

" 

" 

" 

" 

24 


370     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE 
MATERIAL  FOR  BUILDING  60'  0" 


Heights 

Roof 
trusses 

Side  columns 

End  columns 

Knee 

braces 

Roof 
purlins 

Side 
purlins 

Purlin 
finish 
angles 

31 

12'0" 

See 
tables 

4  <s 

2*X2X1 

(each) 
1-5"  I 

3r*<s 

2>iX2XI3e 

1-6"  ]-8  Ib. 

< 

3iX2£Xl 

< 

3X2X1 

32 

14'0" 

" 

" 

1-6"  I 

" 

•• 

" 

" 

33 

16'0" 

- 

4  <s 

3X2Xi 

" 

2  <s 

2*X2Xi 

c 

- 

,,     . 

34 

18'0" 

•• 

4  < 

3iX2*Xi 

1-7"  I  - 

>• 

'. 

" 

•• 

35 

20'0" 

" 

" 

1-8"  I 

" 

" 

" 

" 

MATERIAL  FOR  BUILDING  65'  0" 


36 

12'0" 

4  <s 

3X2X1 

1-5"  I 

2  <s 

1-6"  ]-8  Ib. 

31x2ixi 

3X2X1 

37 

14'0" 

" 

'" 

1-6"  I 

" 

" 

" 

" 

38 

16'0" 

- 

4  <s 

" 

2  <s 

3X2X1 

•' 

" 

» 

39 

18'0" 

" 

•• 

1-7"  I 

" 

" 

" 

" 

40 

20'0" 

i 

1-8"  I 

" 

" 

" 

MATERIAL  FOR  BUILDING  70'  0" 


41 

12'0" 

» 

4  <s 

3X2Xi 

1-5"  I 

2   <s 

3X2Xi 

1-6'   ]-8  Ib. 

<s 

34X2iXA 

< 

3X2X1 

42 

14'0" 

" 

" 

1-6"  I 

45 

" 

43 

16'0" 

•• 

4  <s 

3^X2iXi 

M 

2  <s 

3iX2iXi 

•• 

44 

18'0" 

•« 

" 

1-7"  I 

•• 

" 

" 

45 

20'0" 

•• 

" 

1-8"  I 

» 

" 

" 

" 

STANDARD  BUILDINGS 


371 


XXX. — Continued 
WIDE  X  64'  0"  LONG,  16  FT.  PANELS 


Purlin 
ties 

Purlin 
clips 

Eave  strut 
at  ends 

Bracing 
between 
rafters 

Long'l 
bracing 

Long'l 

struts 

Bracing 
on  tie 
beams 

End 

purlins 

End 
rafters 

i"0 

< 

3X2X1 

2  <s 

3X2X1 

f  "0  rods 

f  "0  rods 

Pipe 
4£"  dia. 

<s 

3£X2}X1 

<s 

3jX2iXl 

1-6"  ]-8  Ib. 

" 

M 

" 

" 

" 

•' 

•• 

" 

- 

« 

" 

•• 

M 

•• 

» 

•• 

•• 

»       ' 

" 

" 

" 

" 

" 

" 

" 

WIDE  X  64'  0"  LONG,  16  FT.  PANELS 


f"o 

< 

3X2Xi 

2  < 

3X2Xi 

f  "0  rods 

|"0  rods 

Pipe 
4i"  dia. 

<s 

3iX2iXl 

<s 

3iX2iXl 

/  1-7" 
\  J-9.75  Ib. 

" 

" 

" 

" 

" 

" 

" 

" 

" 

•• 

•• 

" 

•« 

•' 

•« 

- 

" 

•• 

" 

•« 

" 

" 

" 

" 

" 

" 

" 

41 

" 

" 

" 

" 

" 

WIDE  X  72'  0"  LONG,  18  FT.  PANELS 


f  "0  rods 

3X2X1 

2  < 

3X2X1 

f  "0  rods 

f  "0  rods 

Pipe 
5"  dia. 

3lx2iXJ 

3X2X1 

1-6"  ]-8  Ib. 

" 

" 

" 

" 

•• 

" 

" 

•• 

" 

- 

- 

•• 

" 

- 

- 

" 

•• 

" 

" 

" 

•• 

" 

•• 

•• 

" 

" 

." 

" 

" 

" 

•« 

" 

372     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE 
MATERIAL  FOR  BUILDING  75'  0" 


Heights 

Roof 

trusses 

Side  columns 

End  columns 

Knee 
braces 

Roof 
purlins 

Side 
purlins 

Purlin 
finish 
angles 

46 

12'0" 

See 
tables 

4   <s 

3X2X1 

'(each) 
1-5"  I 

2*<s 

3X2X1 

1-6"  ]-8  Ib. 

<s 

3iX2*Xft 

< 

3X2X1 

47 

14'0 

•• 

" 

1-6"  I 

" 

" 

" 

" 

48 

16'0" 

" 

4  <s 

3iX2fcXl 

« 

2  <s 

3iX2*Xl 

E 

•• 

„     , 

49 

18'0" 

" 

" 

1-7"  I 

•• 

" 

•• 

50 

20'0" 

" 

" 

1-8"  I 

" 

" 

" 

" 

MATERIAL  FOR  BUILDING  80'  0" 


51 

12'0" 

•• 

4  <s 

3X2X1 

1-5"  I 

2  <s 

3X2X1 

1-6"  ]-8  Ib. 

< 

3iX2iX!BB 

<s 

3X2X1 

52 

14'0" 

" 

" 

1-6"! 

" 

" 

53 

16'0" 

« 

4  <s 

3iX2iXl 

» 

2  <s 

3iX2iXl 

•• 

» 

« 

54 

18'0" 

" 

" 

1-7"  I 

" 

" 

" 

55 

20'0" 

" 

" 

1-8"  I 

" 

" 

14 

" 

STANDARD  BUILDINGS 


373 


XXX. — Continued 
WIDE  X  72'  0"  LONG,  18  FT.  PANELS 


Purlin 
ties 

Purlin 
clips 

Eave  strut 
at  ends 

Bracing 
between 
rafters 

Long'l 
bracing 

Long'l 
struts 

Bracing 
on  tie 
beams 

End 
purlins 

End 
rafters 

f'O  rods 

< 

3X2XJ 

2  <s 

3X2X1 

|  "0  rods 

f  "0  rods 

Pipe 
5"  dia. 

<s 

•  3iX2iXi 

<s 

3*X2iXi 

1-6"  ]-8  Ib. 

" 

'< 

" 

" 

" 

" 

" 

<• 

" 

•• 

- 

•• 

- 

- 

•• 

" 

•• 

" 

" 

" 

" 

" 

" 

" 

•• 

•• 

" 

" 

" 

" 

" 

" 

" 

•• 

" 

WIDE  X  72'  0"  LONG,  18  FT.  PANELS 


• 
f'O  rods 

3X2X1 

2  <s 

3X2X1 

i"0  rods 

f'O  rods 

Pipe 
5"  dia. 

<s 

<s 

/  1-7" 
\  ]-9.75  Ib. 

" 

»« 

« 

•• 

" 

«• 

" 

" 

•< 

<• 

" 

... 

" 

'. 

« 

" 

" 

" 

" 

" 

" 

•' 

" 

" 

" 

" 

" 

" 

" 

" 

" 

374     ENGINEERING  OF  SHOPS  AND  FACTORIES 


ilit 

« f  •*  £ 

a  1  ^ 
a  I  a! 


1-s 


li 


0  w  *  fl 

0  fe  fl  g 

**H  O  OJ  O 

-N  -i^  %  c 


•a 


2 


CO 


STANDARD  BUILDINGS 


375 


0> 

s 

I 

S 

1 

§ 
s 

8 
8 

•55 

M 

C 

S 

a 

1 

00 

I 

| 

| 
1 

0> 

1 

g 

1 

c 

1 

0 

1 

1 

i 

1 

i 

(N 

o 

s 

1 

o 

a 

®  ®  .S 

Illl   | 

I 

o  "3  3 

s  '£  £ 

4*    •*»   ,2 

!  :  :  :il 

4 

49 

•g    CO    00 

O      frl         ^H 

CO 

S 

B'-W 

III 

g  g  g  3  .2  « 

2 

1. 

0 

0 

0 

O     fl     C 
«.      §      § 

g  S  S 

3  'S  § 
11.2 

::::§£ 

I 

'S 

* 

i 

CO 

1 

OJ 

§ 

" 

'5S    ®    ® 

ss  *  3 

ft  ^  ^ 
o  i:  «« 

H!f 

"•  "•  "•  ^  1  "^         "^ 

1 

1 

o 

3 

53 

5 

OS 

s  .3  3  3 

3  3  £ 

lllllJ     j 

3 

£ 

i 

: 

§    S83 

g     5*0    0 

1  a  is 

S     '*    ft    ft 

"°   "°     0   ^ 
02      00      .       -fJ 

S       C3       ^     rH 

«  »  S  2  >  ^         § 

o   o   o   o        fl             £ 

between 

•s 

te 

1 

g 

o 

s 

g 

1 

g 

0 

g 

0  e-'o  "s 

j  a  °  ° 

&     &     0      g 

"o  *o   c   > 
o   o  M  -Q 

t,         »H          I            ° 

2  c  c  cs  cu            o> 

!S5  IS    ! 

g 
1 

§ 
£ 

8 

8 

00 

CO 

9 

8 

P-(        02 

H     "^ 

o 

°   °   »  "c 

2 

Q 

CN 

1 

.5 

x 

X  o 

f 

1 

S 

i 

§ 

CO 

o 

CO 

1 

g 

c? 

W)                                         ^  J3 

«) 

o 

s 

s 

S 

-T" 

^           «£^      H^2^ 

0 

£ 

i 

/I 

u 
o 
o 

•§•5        **'xx^  % 

0 

Meas't 

r 

l| 

o 
-0       "0 

^>$       VVVV^  a 

^       7  7  1  7  «  ^ 

•  M  ii  u     (j, 

r                e  e  e   e  V  ^ 

1 

0 

0 

1 

o 

1 

0 

1 

0 

¥\ 

\  t 

V 

A 

3  °  °°  2  S  ><  S 

hsiill 

|    g 

a  ' 
o 

Purlins 

A 

Purlins 

| 

w 

Purlins 

1 

Purlins 

/  g  \ 

S  -g  '3  -S  'g       H 
''            1  II  ||  1  I 

rt     ft 
5J     0 

•o  g 

2 

5 

o 

0 

0 

c 
1 

3 

H 

c 

^ 

H 

376     ENGINEERING  OF  SHOPS  AND  FACTORIES 


CD 
O 

•c 

AH 

£ 

G 

i 

3 

00 

00 
<N 

00 

CO 

00 
<M 

CO 

CO 

CO 
CO 

CO 

CO 

CO 

co 

C5 

CD 

CO 

O5 

.u 

3 
1 

1 

s 

I> 

1 

1 

J 

1 

1 

i 

1 

1 

1 

g 

1 

I 

00 

1 

s 

8 

«s 

il 

S 

ri 

• 

»;' 

CO 
CO 

»0 

• 

10 

i 
s 

1 

g 

1 

§ 

i 

i 

1 

i 

§ 

8 

8 

8 

i 

1 

a 

S 

2 

i  1 

PQ    £ 

1 

"3 

CO 

1 

10 

(M 

(M 

05 

10 
(M 

<M 

05 
(M 

O5 

05 

o 

O5 
(N 

o 

HH     H       ® 

Pi 

«  I 

'S 

W 

i 
•s 

1 

§ 

1 

1 

1 

1 

1 

S 

1 

1 

S 

.1 

PQ   oo     & 

8 
1 

i 
2    ® 

^      c« 

45 

1 

o 

(M 

0 
(M 

O 

S 

O 

(M 

IN 

CM 

s 

us 

CO 

t- 

IQ 

CO 

1 

1 

1 

§ 

§ 

•^ 

S 

i 

1 

1 

1 

§ 

1 

i 

§ 
I 

1 

1 

: 

b 

. 

| 

00 

00 

0) 

^ 

00 

1 

5 

rH 

1 

•H 

S 

1 

'S 

0 

0 

8 

8 

8 

g 

0 

g 

g 

g 

§ 

g 

d 

CD 

1 

i 
5 

^ 

I   I   I 

1 

CO 

i 

CO 

7 

CO 

i 

(N 

CO 

1 

00 

1 

00 

T 

£ 

III 

1 

S 

s 

2 

IN 

CO 

1-1 

CD 

11 

w 

§ 

CO 

O 

§ 

o 

it) 

TABLE  XXX  III.—  Continued 
SIDE  POSTS  AND  KNEE  BRACES 
Weights  are  in  pounds  for  1  post  and  1  knee  brace.  Measurements  are  in  cubic  feet.  Prices  alongside  steamer,  New  York  City 

"8 

• 

•55 

« 

S 

i 

TANi 

I 

DAR 

D  1 

3UI 

LZ> 

1N( 

75 

37 

•4J 

1 

OS 

OS 

OS 

OS 

OS 

OS 

OS 

OS 

OS 

05 

1 

1 

g 

g 

1 

§ 

1 

1 

1 

1 

S 

00 

00 

0> 

o 

& 

+s 

1C 

0 

1C 

1C 

1C 

1C 

1C 

1C 

1C 

1C 

1 

1 

1 

i 

1 

1 

1 

1 

1 

i 

1 

CO 

0> 

2 

1 

O 

o 

o 

o 

o 

s 

o 

•* 

o 

•^ 

o 

•* 

o 

•^ 

I 

8 

CO 

S 

CO 

S 

CO 

CD 

i 

CO 

1 

S 

CO 

1 

i 

§ 

t> 

3 

o> 
o 

£ 

4* 

i 

1C 
CO 

CO 

8 

S 

• 

% 

S 

CO 

CO 

co 

I 

•3 

i 

i 

i 

§ 

i 

i 

i 

1 

1 

1 

£ 
r-1 

i 

1 

CO 

CO 

CO 

CO 

CO 

CO 

CO 

CO 

CO 

CO 

1 
i 

1C 

1 

1 

1 

1 

§ 

i 

1 

1 

§ 

CD 

III 

CO 

„ 

00 

«* 

00 

•* 

00 

"* 

oo 

I 

1 

N 

CO 

3 

CO 

^ 

CO 

I 

CO 

11 

s 

S 

e 

1C 

g 

378     ENGINEERING  OF  SHOPS  AND  FACTORIES 


00        " 

i! 

-j     <& 


o    "§  S   o3   o3   «  «£ 

j    c  a  a  a  a  0 

g  «  xJ  ^2  xi  ^  IS 

5    fa  —  —  —  —  3 

^g,  -wio>oqq  « 

w      .  X'O'Ooood  c 


X  o   d   d   d 


S 


i^§:::::ijo 


OOOOO 
' 


^  "S 

>H 


il^lllll*' I 

g^jS^PHfefefefe'c'S 
H  H  S  > 


1 

: 

SI 

+J 

1 

. 

"§> 

u? 

~r 

i 

1 

§ 

s 

8 

-f 

8 

f 

(N 

<N 

C^J 

rc 

CO 

re 

CO 

1 

; 

: 

s. 

oo 
•^ 
«» 

ij 

co 

+s 

1 

: 
: 

i 

I 

*» 

1 

s 

S 

i 

1C 
0 

§ 

>o 
1 

0 

5] 

§ 

1 

S 

s 

3 

M 

i-H 

'-' 

IN 

N 

(N 

(N 

(M 

<N 

CO 

:c 

o> 
b 

0) 
O 

£ 

i 

: 

8 

5 

: 

! 

- 

• 

1 

•*f 

1 

£ 

I~l 

| 

* 

1, 

•s 

;> 

§ 

q 

1 

1 

S 

2 

1 

« 
1 

1 

§ 

0 

1 

1 

i> 

c 

B 

s 

$ 

AH 

8 

i 

: 
i 

: 

i 

<N 

-i-> 
1 

1 

•s 

i 

1 

1 

I 

(M 

5 

<N 

i 

o 

^0 

O 

IH 
[^- 

O 

-f 

s 

1 

O 

5 

{£ 

• 

' 

6 

£ 

. 
• 

' 

: 

. 
' 

. 

. 

. 

. 

^J 

?* 

' 

0 

s 

1 

s 

5 

i 

t^ 

ro 

2I. 
Ill 

a* 

a  s  c 

/}     0 

j 

5 

8 

S 

s 

3 

S 

s 

§ 

>O 
CO 

R 

>o 
l> 

8 

STANDARD  BUILDINGS 


379 


8£ 
ES 

03 

11 


tH        »-,        M        ^        O 

S,&&&*5 

vassa-g  § 

,M  «e  u»  o  o  $  B 

X  «5   CO   00   06     02     § 

-*>  A  A  A  A  "a   " 


X  d 


d   d  '! 


J   § 


•  rtbOMbDMbOOOrS 

1II11I511 


.2 

i 

4S 

IH 


a  a  a  a  ^3  ^  3 
g  b  fe  fc  2«2  $ 


2  fe  h  ft  fe  fe  $ 


3^ 


li 


S  -2 


i  s 

l^      05 


380     ENGINEERING  OF  SHOPS  AND  FACTORIES 


TABLE  XXXVI 


Ends     of     Buildings. 
Diagrams  showing  General  Construction, 

Pitctf,  6"  to  IS". 

The  Sketches  shown  are  for  ex  Height  of  20 '  to  Eave 
Line.    For  Heights  of  16 '  and  under,  use  one  Jess 
Line  of  Purlins  than  shown  on  Sketches. 


For  Spans  up -to  30  V 


16' /  -for Spat  \only / 


/\ 


/    \ 


"For  Spans  up  to  50'o" 


/\ 


Stru 


Strut 


Purlin 


Tor    Spcxns  to  70 'o! 


^^ 

n 

^Ss. 

. 

f        ^ 

„ 

"^ 

^>^~ 

In           * 

Strut 

Strut 

Stnfr^ 

\     / 

Purh'n 

\      &/ 

\/ 

i!                   ^ 

„ 

^^W 

/\ 

-fc                 -^ 

„ 

<^/x 

/    \ 

^                ^ 

» 

/y1  \ 

For   Spans  up  to  80'0" 


STANDARD  BUILDINGS 


381 


£    3 


H      S 

§  I 


>  a  M: 

tx*  fl   fl 

S  o  ^3  o 

><  "3  |  S 


^  i  ii 

5-§  I 

"^  «S  «2 


.S-9 

I. 


31 


382     ENGINEERING  OF  SHOPS  AND  FACTORIES 


1 

; 

§ 

1 

CO 

3 

g 

8 

1 

0 

1 

1 

I 

8 

i 

§ 

AC 

8 

<N 

I 

(N 

8 

CO 

8 

I 

<N 

|l 

I 

oo 

1 

s 

2 

S 

g 

1. 

S 

Oi 

"*"  W 

1     S  = 

•S 

i 

1 

t-H 

1 

rH 

1 

8 

(N 

0 
§ 

1 

s 
k 

8 

(M 

1 

I 

0) 

.2 

; 

; 

; 

02    —  : 

O             ; 

i 
i 

CO 

1—  1 

i 

- 

§ 

2 

S 

S 

§ 

§!! 

& 

1 

1 

o 

CO 

I 

O 

1 

10 
<N 

1 

1 

I 

1 

I 

| 

ill 

i 

Mils 

§ 

Meas't 

8 

S 

2 

a 

i 

g 

%!i 

1 

S 

O 

i 

1 

S 

CO 

8 

1 

i 

0 

g 

§ 

1 

PQ  J-§'£ 

P 

111 

§ 

£ 

ii 

s 

Meas't 

| 

2 

00 
(N 

2 

10 

8 

ft 

H 

w  S 

1 
1 

1 

1 

I 

1 

0 

1 

1 

I 

1 

I 

I 

(N 

ight  in  pound 
s  table  includ 

Classi- 
fication 

ft 

02 

03 
1 
£ 

I 

02 

Purlins 

02 

Purlins 

ft 
I 

02 

03 

ft 

1 

02 

Purlins 

ft 

05 
£ 

»g 

sl 

£.s 

1 

3 

S 

i 

u 

« 

3 
3 

t 

u 
b 

3 

§ 

g 

STANDARD  BUILDINGS 


383 


-O  d 

d  g 

3  o< 

O  Hi 


I  111 


•55gS§c«c«o3« 

g  i  §,  a  a  a  a^ 
w-gc^cow-^ws-g 


jiiii-a 

^s    ro    y    -»    ,T* 


ii 


3    3 


^soooo^ 

jd    ^    US    t>    O5    —I    CO     t-, 
*      3    ^  rH     ^H      O 

^•siiuiL 

^•§^[2333  ft^ 

t^a3oo)o>aia>5'1'^' 


8 

£ 

i 

; 

i 

d 

| 

; 

; 

1 

•3 

1 

1 

1 

00 
"5 

1 

1 

s 

0> 

1 

2 

1 

s 

I 

I 

i 

§ 

1 

1 

§ 

g 

1 

d 

I 

L 

o 

£ 

'. 

'. 

! 

trusses  ( 

1 

1 

•; 

I 

j 

'  between 

1, 

•8 

a 

<N 

g 

CO 

us 

i 

1 

§ 

rH 

1C 

1 

8 

8 

§ 

£ 

_^ 

* 

*» 

3 

^j 

• 

§ 

1 

» 

CO 

0 

§ 

CO 

i 

oo 

o 

§ 

• 

I 

£ 

; 

.j 

"1 

* 

0 

§ 

1 

O 
<N 

o 

1 

i 

o 

3 

• 

1 

d 

I 

* 

CO 

s 

1C 

.8 

"5 

flb 

s 

• 

o 

? 

§ 

384     ENGINEERING  OF  SHOPS  AND  FACTORIES 


Q 

X     I 


13  a 
.s  2 


s  s,  * 
a  §  §3 

O*   fi 

a. a  | 

'M  *  ^ 


I 


O  jn 

a  ~tf 


STANDARD  BUILDINGS 


385 


TABLE  XL 

Details  and  WTeights  of  Connections  for  Bracing 

between  Trusses  at  Tie  Beams,  and  Posts  to  Tie 

Beams. 

Note. — The  Weights  given  include  only  the  Weights 

of  Material  for  which  sizes  are  given  in  the  Details, 

and  the  Measurements,  etc.,  for  the  same. 


Soft.  Chord  of  Tie  Beam 


Connection  for  Bracing 
between  Tie  Beams  to 
In  rer:  Posts  of  End  Frame  \ 
Weight  of  One  =  30  Ibs. 


Weight  of  One 


28  Ibs. 


^Purlin 


ft*  of 

*  Corner 
Frame. 
Weight  of  One  =  S2  Ibs. 


Framing  L 


Pos+s  of  'End  Frame;  if  Posfs 

^ro   r  Beams  . 
We^hf  of  One  =  19  As. 


Connected  to  Inter.  Posts 
of  End  Frame  where  a  Latticed  M  ,, 
Strut  extends  across  the  End/y~ 
at  Eaves. 
Weight  of  One  =  17  Ibs. 


5U™A 


io 


•;•  oj 


Strut 


25 


386     ENGINEERING  OF  SHOPS  AND  FACTORIES 


p 

t 

2 

f 

CO 

3 

1 

CO 
<N 

o 

2 

CO 

rH 

00 

CO 

I 

12-14-16 

1 

CO 
<N 

1 

X 

1*  : 

HN 
(N 

B 

X 

_ 

', 

00 

5 

1-1 

CO 

03 

V 

rV, 

5 

x 

X 

X 

HN 

i 

(N 

CO 

<N 

X 

: 

: 

X 

: 

• 

: 

X 

: 

: 

: 

rH 

^ 

CO 

CO 

03 

V 

V 

V 

c 

d 

x 

x 

X 

x 

X 

X 

X 

1 

2 

* 

(N 

x 

: 

: 

x 

CO 

(N 

X 

X 

CO 

: 

: 

(N 

X 

<N 
X 

CO 
03 

CO 

93 

V 

03 

V 

CO 

V 

03 

V 

CO 
03 

V 

V 

0} 

V 

s 

w 

x 

X 

X 

H* 

x 

X 

X 

H« 

|^ 

H« 

v 

CN 

X 

<N" 

£ 

fr4 

X 

. 

X 

(N 
X 

X 

. 

. 

X 

X 

X 

rH 

V 

CO 

V 

03 

V 

CO 
03 

V 

00 
03 

V 

CO 

V 

CO 

V 

«* 

rf 

* 

x 

x 

X 

x 

X 

^ 

c^ 

c^ 

-M 

CN 

C^l 

0 

x 

: 

- 

X 

X 

X 

- 

X 

rH 

5 

CO 

r\i 

00 

CO 

w 

03 

DQ 

V 

V 

V 

V 

•HH 

V 

t 

-t 

a" 
a 

t 

i 
P 

3 
3 

c 

3 

u 

T 

3 
M 

1 

3 

I 

I 

STANDARD  BUILDINGS 


387 


J 

•i 

S 
1 

12-14-16 

I 

CD 

1 

1 

CO 

1 

CD 

I 

CO 

i 

X 

X 

HN 

X 

j 

c? 

HO 

IN 

00 

: 

! 

: 

X 

He* 

x 

X 

: 

: 

: 

: 

CO 

CO 

CO 

V 

V 

V 

* 

* 

X 

X 

X 

CO 

: 

- 

- 

X 

X 

X 

: 

: 

: 

: 

1-1 

CO 

CO 

CO 

V 

V 

V 

rt* 

.  § 

•5 

•i 

* 

£ 

x 

X 

X 

X 

X 

d 

Hn 

HP* 

HN 

H|N 

1 

• 

(N 

<N 

C4 

<N 

IN 

fi 

i 

•^ 

: 

: 

: 

: 

: 

X 

x 

x 

x 

x 

~£ 

rH 

CO 

CO 

CO 

CO 

CO 

1 

V 

V 

V 

V 

V 

j 

Q 

•6 

^ 

»5 

-4* 

* 

X 

X 

X 

X 

X 

£ 

CN 

<N 

s 

: 

: 

: 

t 

X 

X 

x 

X 

X 

CO 

CO 

CO 

CO 

V 

V 

V 

V 

V 

0 

i 

tJ 

N4 

I 

c 
c 

3 

| 

S 

^ 

D 

1 
t 

0 

c 

c 

8 

388     ENGINEERING  OF  SHOPS  AND  FACTORIES 


1  s 


*      .2 


II 

CO    — 

•s-s 

?! 


^ 


•a 


•813 

2  S 
.a  S 
•*  »o 

43     43 

1  S  oo  o 

fss 


5        C 

a  I  <N  oo 

I  fill 

I    .  §  ^  .2  -2 

lllfl! 

p,  ^  ^1     ^  ^1 

O     I      O     I      O    O 

•h       h    r^  P^ 


CO 

•c 

PU 

x 

CO 

8 

CO 

X 

s 

< 
X 

S 

CO 

00 
(N 

06 

(N 

1 

X 

(N 

j 

X 

CO 

X 

<N 

; 

cc 
X 

rJM 
0) 

X 
?1 

X 

X 

CO 

oT 

— 

I 

— 

"M 

C 

~^- 

'i 

— 

CC 

be 

C 

— 

GJ 

— 

43rf.j 

g 

c 

*** 

0 

^ 

0 

•^ 

§ 

^ 

l-H 

8 

(N 

CO 

S 

^ 

§ 

o 

co 

S 

S 

X 

CO 

X 

CO 

x 

1C 

•R 
x 

^ 

-R 
x 

OJ 

He* 

CO 

. 

ro 

r-? 

S 

"a 

o> 

CM 
X 

(N 

; 

X 
(N 

» 

x 

X 
Jl 

x 

CO 

GO" 

7 

aT 
"bC 

a 

g 

tt 

S 

i 

of 

I 

1 

CO 

| 

c 

"bd 

C 

s 

§ 

& 

g 

o 

« 

S 

£ 

X 

•*» 
(N 

CO 

X 

CO 

CO 

X 
» 

10 

X 

ro 

X 

05 

bC 

£ 

•^ 

X 

X 

X 

X 

X 

•s 

CD 

o3 

(N 

<!N 

r-'CS 

-•v? 

. 

CO 

a 

M 

x 

aT 

'    '. 

of 

g 

I 

g 

! 

s 

__X 

4 

i 

J* 

3 

o 
-t 

| 

1 

§ 

S 

-*« 
X 

s 

CO 

x 

g 

X 

s 

x 

a> 

-R 
x 

' 

00 

"a 

0) 

s 

Ang's,  2X2* 

i 

Ang's,  2X3 

i 

re 
X 

c-'i 

.« 

"bfi 
G 

1 

x 

CM 

oa" 

"M 

c 

J 

Tt< 

X 
N 

to" 
"tc 

G 

S 

CO 

1 

i 

g 

s 

"5 

i-i 

S 

A 

X 

CO 

X 

CO 

X 

WM 
CO 

CO 

HS 

x 

•+< 

CO 

O5 

* 

X 

rH 

43 

*« 

X 

X 

X 

X 

X 

i 

V 

<N 

«" 

« 

(N 

CO 

"bC 

cc 

43 

a 

— 

C 

4 

• 

U 



45 



0 

CO 
(N 

1 

1 

1 

•51 

b 

b 

b 

b 

0 

s   c 

1 

b 

N 

fe 

b 

30 

J 

BIBLIOGRAPHY  389 


BIBLIOGRAPHY 

Treatises. 

Cost  Keeping  and  Management H.  A.  EVANS. 

Design  and  Construction  of  Metallurgical 

Plants OSCAR  NAGEL. 

Efficiency HARRINGTON  EMERSON. 

Factory  Costs F.  E.  WEBNER. 

Factory  Organization HUGO  DIEMER. 

Industrial  Engineering CHAS.  B.  GOING. 

Industrial  Plants CHAS.  DAY. 

Mill  Building  Construction  (1900) H.  G.  TYRRELL. 

Mill  Buildings  (1910) H.  G.  TYRRELL. 

Mill  Construction C.  T.  MAIN. 

Millwrighting HOBART. 

Millwrighting SWINGLE. 

Modern  Machine  Shops O.  E.  PERRIGO. 

Shop  Management F.  W.  TAYLOR. 

Specifications  for  Buildings C.  C.  SCHNEIDER. 

Works  Management KNOEPPEL. 

Works,  Wages  and  Profit H.  L.  GANTT. 

Journalistic  Articles. 

Altruism  and  Sympathy  in  Administration .   J.  H.  PATTERSON. 

Engineering  Magazine,  Jan.,  1901. 

Armories — Steel  Framing  for H.  G.  TYRRELL. 

Architect's  and  Builder's  Magazine,  Oct.,  1901. 
Bibliography  of  Works  Management HUGO  DIEMER. 

Engnieering  Magazine,  July,  1904. 
Boiler  Shops  at  Grafenstaden,  Alsace. 

Zeits.  d.  v.  Deutscher  Ing.,  Oct.  7,  1899. 
Burnside    Shops    of    the    Illinois    Central 
Ry.  Co. 

Engineering  News,  June  18,  1896. 
Capital  and  Labor  Harmony ANDREW  CARNEGIE. 

Gassier s  Magazine,  July,  1903. 
Chicago     and     Northwestern     Shops     at 
Chicago. 

American  Engineer  and  Railroad  Journal,  March,  1899. 
Cincinnati     Milling     Machine     Company's 

Shops E.  M.  CHACE. 

Machinery,  N.  Y.,  Sept.,  1900. 
Coal  Hoisting  Towers H.  G.  TYRRELL. 

Engineering  News,  May,  1901. 
Coal  Mine  Tipples "  " 

Engineering  and  Mining  Journal,  Feb.  2,  1905. 
Concord  Shops  of  the  B.  &  M.  R.  R. 

American  Engineer  and  Railroad  Journal,  March,  1898. 


390     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Comfortable  Shops. 

Iron  Age,  Nov.  8,  1900. 
Comparative    Cost    of    Wood-  and    Steel- 
frame  Factory  Buildings H.  G.  TYRRELL. 

Railroad  Gazette,  Oct.  1904. 

Carpentry  and  Building,  Nov.,  1905. 
Comparative    Cost    of    Wood,    Reinforced 

Concrete  and  Steel  Buildings .*  .  .  .        "  " 

Engineering  Magazine,  June,  1912. 
Cooling  Shops  by  Evaporation A.  PAPIN. 

Genie  Civil,  May  1,  1909. 
Cost  of  Concrete  Buildings. 

National  Association  of  Cement  Users,  Report  of  1909. 
Cost  of  Remodeling  an  Old  Factory W.  S.  ROGERS. 

Machinery,  N.  Y.,  April,  1898 
Design  of  Industrial  Buildings H.  F.  STIMPSON. 

Engineering  Record,  May,  1909. 

Design  of  Industrial  Works G.  H.  GIBSON. 

A.  HOME  NORTON. 

The  Mechanical  Engineer,  July  30,  1909. 
Design  and  Construction  of  Modern  Engi- 
neering Shops J.  H.  HUMPHREYS. 

The  Mechanical  Engineer,  Dec.  13-20,  1902. 
Design    and    Construction    of    Industrial 

Buildings D.  C.  N.  COLLINS. 

Engineering  Magazine,  Sept.,  1907. 
Domes,  Steel  Framing  for H.  G.  TYRRELL. 

Architect's  and  Builder's  Magazine,  March,  1905. 
Drafting  Office  Rules "  " 

Engineering  News,  March  23,  1905. 
Drainage  of  Works  and  Buildings " 

Canadian  Engineer,  Nov.-Dec.,  1901. 
Drawings,  Cost  of,  for  Structural  Work. ...         "  " 

Iron  Age,  July,  11  1901. 
Economic  Theory  of  Factory  Location HUGO  DIEMER. 

Railway  Age,  March  18,  1904. 
Elements  of  Modern  Shop  Arrangement. 

Railroad  Gazette,  June  15,  1900. 
Engineering  of  Industrial  Buildings D.  C.  N.  COLLINS. 

Iron  Age,  Dec.  1,  1904. 
Engine  Foundations. 

Engineering-Contracting,  March  31,  1909. 
Estimating  Structural  Work H.  G.  TYRRELL. 

Architect's  and  Builder's  Magazine,  Jan.,  1903. 
Export  Trade  in  Structural  Steel 

Iron  Age,  June  13,  1901. 
Factory  Foot  Bridges "  " 

Carpentry  and  Building,  1905. 


BIBLIOGRAPHY  391 

Factory  Construction  and  Arrangement.  .  .    L.  P.  ALFORD. 

American  Society  of  Mechanical  Engineers,  Oct.,  1911. 
Fire  Protection  of  Railroad  Shops H.  S.  KNOWLTON. 

Railway  Age,  June  9,  1905. 
Fire  Drill H.  F.  J.  PORTER. 

Gassier s  Magazine,  August,  1905. 
Fire  Department  for  Shops. 

American  Machinist,  Sept.  23,  1897. 
Floors  for  Machine  Shops 

Iron  Trade  Review,  Oct.  26,  1905. 
Floors,  Shop H.  M.  LANE. 

Engineering  Digest,  April,  1911. 
Floors,  Cement ALFRED  GRADENWITZ. 

Cement  Age,  Dec.,  1908,  and  Oct.,  1909. 
Floors,  Basement J.  E.  SWEET. 

Transactions  American  Society  of  Mechanical  Engineers, 

May,  1897. 
Floors,  Shop L.  C.  WASON. 

American  Machinist,  Oct.  26,  1911. 
Foundry  Design G.  K.  HOOPER. 

Iron  Age  Jan.  5-12,  1911. 
Foundry  Design J.  HORNER. 

Engineering,  Jan.  21,  1910. 
Gary,  Indiana,  Steel  Plant. 

Engineering  Record,  Oct.  9,  1909. 
Gateshead,    England,    The    Northwestern 
Railway  Works. 

Engineering,  London,  Dec.  18,  1896 
Glasgow,  Works  of  Sir  William  Arrol  &  Co. 

Engineering,  London,  May  18,  1900. 
Higher  Law  in  the  Industrial  World H.  F.  J.  PORTER. 

Engineering  Magazine,  August,  1905. 
Hunslet,  Leeds,  Works  of  Graham,  Morton 
&Co. 

Iron  and  Coal  Trade  Review,  March  18,  1904. 
Ideal  Blacksmith  Shop A.  W.  MCCASLIN. 

Railway  Master  Mechanic,  Nov.,  1904. 
Impressions  of  American  Workshops A.  J.  GIMSON. 

Institute  of  Mechanical  Engineers,  Jan.  20,  1905. 
Industrial  Works GIBSON. 

Mechanical  Engineer,  July  30,  1909. 
Iron  Mill  Buildings J.  W.  SEAVER. 

Transactions,  Engineer's  Society  of  Western  Pennsylvania,  1892. 
Laying  Out  of  Workshops JOSEPH  HORNER. 

Pages  Magazine,  March,  1903. 
Lighting  of  Shops H.  C.  SPILLMAN. 

Electrical  World,  Feb.  23,  1911. 
Machine  Foundations. 

Mechanicnl  World,  Jan.  22,  1909. 


392     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Machine  Shop  Management H.  F.  L.  ORCUTT. 

Engineering  Magazine,  Jan.  to  Aug.,  1899. 
Machine  Shop  Roofs J.  E.  SWEET. 

Cassier's  Magazine,  Aug.,  1905. 
Market  Buildings :  .   H.  G.  TYRRELL. 

Architect's  and  Builder's  Magazine,  July,  1901. 

Mill  and  Shop  Construction. BURR  K.  FIELD. 

Connecticut  Association  of  Civil  Engineers,  1894. 
Mill  Buildings — A  Discussion ALBERT  SMITH. 

Journal  Western  Society  of  Engineers,  Feb.,  1911. 
Mill  Building  Construction G.  H.  HUTCHINSON. 

Engineer's  Society  of  Western  Pennsylvania,  Oct.,  1892. 
Modern  Machine  Works  of  Loewe  &  Co.,  Berlin. 

Zeitch.  d.  V.  Deutcher  Ing.,  Sept.  30,  1899. 
Modern  Machine  Shop  at  Prague PROF.  T.  DEMUTH. 

Zeitsch.  D.  V.  Deutscher  Ing.,  Oct.  23,  1897. 
Modern  Machine  Shop  in  Prussia E.  ALBERTS. 

Stahl  und  Eisen,  Sept.  1,  1901. 
Modern  Machine  Shop  Location H.  L.  ARNOLD. 

Engineering  Magazine,  April,  1896. 
Montreal   Shops   of  the   Canadian  Pacific 

Railway  Co W.  O.  QUEST. 

American  Engineer  and  Railway  Journal,  Dec.  1,  1904. 
National  Cash  Register  Works,  Dayton,  Ohio.     A  series. 

American  Machinist,  March  25,  1897. 
Omiya  Shops  of  the  Nippon  Railway  of 

Japan W.  C.  TYLER. 

Railway  and  Engineering  Review,  Oct.  1,  1898. 
Operation   of   Hungarian   Railway   Work- 
shops    RUDOLF  NAGEL. 

Glaser's  Annalen,  Feb.  1,  1900. 
Pavements H.  G.  TYRRELL. 

Canadian  Engineer,  Feb.,  1902. 
Pencoyd  Iron  Works — A  Serial. 

American  Machinist,  June  25,  1903. 
Photography  for  the  Shop. 

American  Society  of  Mechanical  Engineers,  Nov.,  1909. 
Planning  of  Factory  Buildings HUGO  DIEMER. 

Engineering  Magazine,  March  24,  1904. 
Planning  of  Industrial  Buildings H.  F.  STIMPSON. 

Engineering  Record,  May  29,  1909. 
Progress  in  the  Design  of  Roofs  since  1850.   EWING  MATHESON. 

Engineering,  London,  Jan.  9,  1903. 
Railroad  Shops WALTER  G.  BERG. 

Railroad  Gazette,  March  13,  1903. 
Railroad  Shops  and  their  Equipment. 

Iron  and  Coal  Trade  Review,  April,  10,  1896. 
Railway  Shops R.  H.  SOULE. 

American  Engineer  and  Railway  Jour.,  Feb.,  1903. 


BIBLIOGRAPHY  393 

Roofing  Existing  Shops R.  H.  FOWLER. 

Institute  of  Mechanical  Engineers,  July,  1903. 
Roofs  and  Roof  Coverings. 

Engineering  and  Mining  Journal,  Sept.  5,  1903. 
Rolling  Mill  Building  at  Middletown,  Ohio. 

Engineering  Record,  July  20,  1901. 
Rolling  Mill  at  Monterey,  Mexico O.  GOLDSTEIN. 

Stahl  und  Eisen,  June  15,  1904. 
Roundhouses. 

American  Society  of  Mechanical  Engineers,  July,  1910. 
Schenectady  Shops  of  the  General  Electric 

Co S.  D.  V.  BURR. 

Iron  Age,  Jan.  4,  1900. 
Shipping  Directions  for  Structural  Steel ...   H.  G.  TYRRELL. 

Iron  Age,  April  25,  1901. 
Shop  Cranes " 

Iron  Age,  Jan.  19,  1905. 
Shop  Construction OSCAR  E.  PERRIGO. 

Machinery,  Oct.-Nov.,  1902. 
Shop  Design "  " 

Iron  Trade  Review,  Dec.  29,  1910. 
Shop  Esthetics R.  L.  TWEEDY. 

American  Architect,  June  14,  1911. 
Some  Features  of  Modern  Shops S.  T.  FREELAND. 

American  Machinist,  Nov.  26,  1896. 
Steam   Engineering   Plant   at    New   York 

Navy  Yard C.  H.  MATTHEWS. 

Jour.  American  Society  of  Naval  Engineers,  Nov.,  1901. 
Steel  Buildings  for  Export H.  G.  TYRRELL. 

Engineering  News,  April  11,  1901. 
Storage  Pockets "  " 

Railroad  Gazette,  Oct.,  1901. 
Sturtevant  Shops,  Hyde  Park,  Mass W.  B.  SNOW. 

Engineering  News,  Oct.  30,  1902. 
Suggestions  for  Shop  Construction F.  A.  SCHEFFLER. 

Transaction  American  Society  of  Mechanical  Engineers,  Dec.,  1903 
Suburban  Settlement — "Homewood" E.  R.  L.  GOULD. 

American  Review  of  Reviews,  July,  1897. 
Truce  Between  Capital  and  Labor CARROLL  T.  FUGITT. 

Gassier s  Magazine,  Sept.,  1905. 
United  Shoe  Machinery  Shops  at  Beverly, 
Mass. 

Engineering  Record,  April,  1905. 
Ventilation  of  Shops. 

Practical  Engineer,  June  24,  1910. 
Warehouses  and  Factories  in  Architecture .    RUSSELL  STURGIS. 

Architectural  Record,  Jan.,  1904. 
Weight  of  Steel  Roof  Trusses ' H.  G.  TYRRELL. 

Engineering  News,  June,  1900. 


394     ENGINEERING  OF  SHOPS  AND  FACTORIES 

Weight  of  Trusses  and  Girders  for  All  Spans 

and  Loads H.  G.  TYRRELL. 

Engineering,  London,  July  25,  1902. 
Workman's  Dwellings  at  the  Krupp  Steel 
Works. 

Gluckauf,  May  29,  1897. 
Works  Design  as  a  Factor  in  Manufacturing 

Economy . . f»  .   HENRY  HESS. 

Engineering  Magazine,  July,  1904. 

Workshops  of  Modern  Type A.  PRINGLE. 

Canadian  Society  of  Civil  Engineers,  Dec.,  1903. 


INDEX 


Acid   etching  of   concrete   surfaces, 

138 

Adhesion  of  concrete,  111 
Air  distribution,  system  of,  233 

economizers,  237 

supply,  system  of,  231 

washing  system,  251 
American    Institute    of    Consulting 

Engineers,  7 

Arch  roof,  stress  sheet,  98 
Armories,  weight  of,  93,  97 
Asphalt  floors,  168 


B 


Beam  hangers,  65 
Beams  of  concrete,  117 
Bethlehem  shapes,  71 
Bibliography   of   factory   buildings, 

389 

Blue  printing,  205 
Boarding,  thickness  and  span,  200 
Brick  arch  floors,  176 

floors,  169 
Buckeye  floor,  174 
Building  frames,  stress  in,  48 

lot,  selection  of,  16 

materials,  kinds  of,  52 

plans,  by  whom  made,  1 

types,  selection  of,  52 
Bunkers,  suspension,  221 


Canadian  Northern  shops,  29 
Cantilever  cranes,  334 
Car  houses,  212 
shops,  212 

Ceiling,  value  of  light  ones,  270 
Ceilings,  flat  or  ribbed,  184 


Cement  concrete  floors,  163 

production  of  the  United  States, 

103 
Charges  of  consulting  engineers,  5,  6, 

7,  8 

Chimneys,  316 
City  location  for  plants,  12 
Cleanliness  and  order  as  protection 

against  fire,  324 

Climate,  effect  on  selection  of  dis- 
trict, 16 

Coal  storage  bins,  219 
Code  of  ethics  for  engineers,  7 
Coffer  dams,  157 
Coloring  concrete,  131 
Columns  50 

of  concrete,  116 
schedule,  a  typical  one,  74-88 
Comparative  cost  of  concrete  and 

steel,  151 

of  wood,  concrete  and  steel,  147 
of  wood  and  concrete,  149 
Concrete  beams,  117-118 

design  of,  120 
buildings,  cost  of,  140 
construction,     advantages      of, 

103 

disadvantages  of,  104 
coal  and  ash  pockets,  224 
floors,  beam  and  slab  type,  179 
framing,  102 
materials,  106 
roofs,  201 

surface,  treatment  of,  127 
surface  removal,  131 
upper  floors,  178 
Construction,  354 
Contracts,  355 

between   engineer   and    owner, 

10-11 

Consulting  engineers,  charges  of,  5 
Co-operation  of  different  shops,  35 


395 


396 


INDEX 


Cost  charts  for  shops,  68-70 

estimates,  32 

estimate  for  structural  plant,  37 

modification  of,  to  suit  location, 
VIII 

of  heating,  238 

of  land  and  area  required,  14 

of  lighting,  273 

of  steel  buildings,  99 
Cotton  mills,  214 
Crane  girders,  lateral  stiffness  of,  50 

specifications,  328 
Cranes,  327 


D 


Departments,  arrangement  of,  27 
for  fire  protection,  320 

Depreciation,  54 

Design  of  concrete  buildings,  108 

Direct  radiation,  231 

District,  selection  of,  12 

Doors,  197 

Domes,  framing  of,  89 

Darfting  office,  203 

Drainage  of  buildings,  281 
of  industrial  works,  281 
of  plants,  286 

Drawings  for  buildings,  42 

Dust  formation  on  floors,  167 


Earth  floors,  158 

Economics  of  factory  construction, 

18 
Eliminator,  action  of,  253 

construction  of,  252 
Ends  of   buildings,  arrangement   of 

framing,  380 
Engine  foundations,  157 

houses,  circular  and  rectangular, 

208 

Engineers  and  their  services,  1 
Engineering  service,  cost  of,  4 
Engineers'  Club  of  St.  Louis, 

schedule  of  charges,  6 
Erection  of  concrete  buildings,  124 
tools  and  machinery,  39 


Esthetic  treatment,  44 
Estimating,  336 
Estimates  and  tenders,  354 
Essentials  of  good  framing,  53 
Exhaust  steam  heating,  237 
Expansion,  provision  for,  27 
Extension  of  plant,  36 


Factory  lighting,  257 

an  example,  275 
Fan  system  for  heating,  229 
Fire  drill,  325 

extinguishers,  323 
Fireproofing  of  structural  concrete, 

110 

Fireproof  material,  320 
Fire  protection,  319 
systems,  321 

streams,  314 
Flat  slab  floors,  183 

slabs,  strength  of,  185 
Floors,  area  and  elevation  of,  24 

asphalt,  168 

brick,  169 
arch,  176 

cement  concrete,  163 

concrete  upper,  178 

earth,  158 

flat  slab  type,  183 

granolithic,  166 

metal  arch,  175 
plate,  176 
trough,  176 

plank,  159 

recommended  types,  170 

slow  burning,  172 

tar  concrete,  162 

wood  block,  159 

loads,  47 

Ford  Motor  Works,  24 
Forge  shops,  206 
Formulae  for  concrete  floors,  182 
Foundations,  152 

walls,  154 
Foundries,  207 
Friction  of  water  in  pipes,  315 


INDEX 


397 


Gables,  one  or  two,  59 
General  design  of  buildings,  42 
Grade  of  lot,  17-35 
Granolithic  floors,  166 
Ground  floors,  158 
Growth  of  plants,  VII 


H 


Hair  cracks  on  concrete,  125 
Health  conditions  in  factories,  359 
Heating,  229 

by  floor  radiation,  244 
Heat  losses,  230 
Hoisting  towers,  226 
Horse-power  to  raise  water,  313 


Illumination,  importance  of,  260 

of  vertical  surfaces,  268 
Industrial  engineers,  VII 
qualifications  of,  4 
Inspection  for  fire  risk,  323 
Insurance,  54 


K 


Knee  braces,  49 


Labor  supply  and  wages,  15 
Lamps,  height  of,  265-267 

number  of  per  unit  of  floor  area, 
265 

selection  of,  265 

Lighting  as  related  to  effective  man- 
agement, 259 

drawings,  271 

glare  in,  264 

overhead  method  of,  263 

requirements,  261 

units,  candle-power  of,  258 
Loads  on  foundations,  152 
Loading  apparatus,  334 

facilities,  39 


Location  of  factories,  34 
Long  span  roofs,  92 

M 

Machines,  arrangement  of,  22 

schedule  of,  21 
Machine  shops,  206 
Machinery  connection  to  concrete 

floors,  121 

Manufacturing  district,  selection  of, 
12 

city  or  suburb,  12 
Market  buildings,  60 

for  manufactured  products,  16 
Material  benefits  for  employees,  361 

and  mixing  for  concrete,  106 
Metal  arch  floors,  175 

framing,  71 

trough  floors,  176 
Method  of  construction  for  buildings, 

37 
Methods  of  management,  20 

of  manufacture,  18 
Monitors,    longitudinal    and    trans- 
verse compared,  57 
Monitor  framing,  estimate  for,  375 
Monolithic  and  separately  moulded 

members,  114 

Motors  for  yard  haulage,  333 
Multiplex  floors,  175 


N 


Nailed  joints,  value  of,  64 
National  Cash  Register  Works,  13 

Portland  Cement  Co.  Plant,  29 
North  light  roofs,  58 


Oscillation  of  buildings,  53 


Painting  concrete,  129 
Paint  shops,  heating  of,  241 
Paper  mills,  heating  of,  241 
Partitions,  194 


398 


INDEX 


Photography,  use  of,  43-205 

Picking  concrete  surfaces,  135 

Piers,  154 

Piles,  156 

Pipes,  carrying  capacity  of,  247 

Pits  in  engine  houses,  211 

Plank  floors,  159 

safe  load  on,  172 
Plant  location,  VIII 
Plastering  concrete,  130 
Plate  floors,  176 
Plumbing  fixtures,  284 
Pneumatic  system  of  drainage,  293 
Portland  cement,  history  of,  102 
Posts  and  knee  braces,  estimates  for, 

376 
Power,  39 

houses,  214 

nearness  to  source  of,  15 
Preliminary    design    for    structural 

plant,  34 

Preparation  of  concrete  surfaces,  131 
Preparatory  design  of  plant,  30 
Preservation  of  metal,  71 
Profit  on  investment,  41 
Pumps,  capacity  of,  312 


Rafter  bracing,  estimates  for,  383 
Raw  materials,  nearness  to,  15 
Recreation,  provision  for,  362 
Reinforced    concrete    frames    with 

brick  walls,  52 
Reinforcing  bars,  107 
Reflectors  for  illumination,  269 
Repairing  granolithic  floors,  168 
Roof  outlines,  55 

purlins,  estimates  for,  378 

truss  coefficients,  48 

trusses,  estimates  for,  374 
Roofs  and  roofing,  199 
Round  houses,  207 

house  heating,  239 
Rubbing  concrete  surfaces,  135 


Sand  blasting,  133 


.  Scope  of  plants,  36 

Scrubbing  concrete  surfaces,  135 

Separately  moulded  members,  111- 
145 

Sewage,  conservation  of,  294 
disposal  of,  294 

Sewers,  flushing  of,  292 
ventilation  of,  290 

Shafting    attachments    to    concrete 
beams,  123 

Sheet  piling,  157 

Shingles,  concrete,  201  *" 

Shipping  facilities,  15-25 

Shower  baths,  285 

Side  posts,  size  of  material  for,  386 

Similar  plants  to  the  proposed  one, 
particulars  of,  20 

Size  of  lot,  34 

Social    relations  •  for    factory    em- 
ployees, 357 

Soil,  area  on,  153 

Soils,  bearing  power  of,  152 

Slow  burning  or  mill  construction,  52 

Specifications,  51 

Spiral  reinforcing  for  concrete  col- 
umns, 116 

Spray  chambers  for  air  washing,  253 

Standard  building  tables,  364 

Stand  pipes,  308 

Statistics  of  industries,  VIII 

Steam  heating,  243 

Steel  frame  buildings,  cost  of,  98 
with  brick  walls,  52 

Stephenson's  experiments  for  wind 
pressure,  45 

Stirrups  for  concrete  beams,  120 

Storage  pockets,  219 
tanks,  297 

Storing  and  receiving  space,  25 

Stress  analysis  in  building  frames,  48 

Suburban  districts,   advantages   of, 
13 

Superintendence,  356 

Surface  coating  of  concrete,  128 
defects  of  concrete,  125 
finish  of  concrete,  125 
removal  on  concrete,  131 

Surroundings  of  plant,  360 

Switches  for  lighting,  271 


INDEX 


399 


Tanks,  297 

capacity  of,  311 

standard  dimensions  of,  310 
Tar  concrete  floors,  162 
Tee  beams,  118 
Textile  mills,  heating  of,  240 
Theory,  applied  to  concrete  building, 

109 

Tie  beam  bracing,  384 
Tile,  concrete,  201 
Tooling  concrete,  133 
Track  arrangement  in  yards,  331 
Train  shed  roofs,  table  of,  97 
Treatises  on  factory  buildings,  389 
Treatment  of  concrete  surfaces,  127 
Tungsten  lamps,  267 

lighting  system,  274 
Turntables,  210 


U 


Unit  frames  for  concrete  beams,  119 

stresses,  47 
United    Shoe   Machinery   Shops   at 

Beverly,  106 
Upper  floors,  172 


Veneering  concrete  surfaces,  130 
Vibration  of  buildings,  53 


W 


Walls,  188 

Wall  purlins,  size  of,  388 
Waste  heat,  utilization  of,  236 
Waterproofing  concrete,  123 
Water  supply,  17-297 

towers,  298 
Weight  of  galvanized  iron  pipes,  245 

of  steel  frames  for  multi-story 

buildings,  100 
Welfare  features,  357 
Wind  pressure,  44 
Windows,  196 

Winnipeg    shops    of    the    Canadian 
Northern  Ry,  28-29,  213 
Wooden  buildings,  52 

columns,  details  for,  64 
Wood  block  floors,  159 

floors,  172 

with  steel  beams,  174 

framing,  61 

mill  buildings,  cost  of,  65,  67 
Working  units  for  concrete,  111 


Vacuum  system  of  heating,  239 


Yards,  arrangement  of,  25,  26,  35, 
330 


292713 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


